PESHAWAR: Unidentified gunmen entered Bacha Khan University in Khyber Pakhtunkhwa’s Charsadda town Wednesday and opened fire on students and faculty members as they gathered at the school for a poetry recital to commemorate the death anniversary of the activist and leader whom the school is named after.

The mastermind of the APS Peshawar attack, Umar Mansoor, of the banned Tehreek-i-Taliban Pakistan (TTP) Geedar group has claimed the attack through a post on his Facebook page, adding that four attackers were sent to the university.

However, a spokesperson from the TTP, Mohammad Khorasani, issued a conflicting statement shortly after Mansoor's claim, in which Khorasani condemned the attack, terming it "against Shariah".

Khorasani also warned that those "using the naming of TTP will be brought to justice".

As the military announced the end of the clearance operation, mass casualties were feared in the attack reminiscent of the deadly December 2014 terrorist attack on the Army Public School in Peshawar which left over 140 dead — most of them students.

Sources added that the four attackers were wearing suicide vests but were killed by security forces' before they could detonate their explosives.

Key updates:

• Police confirm 21 dead

• Military says 4 attackers killed, gunfire over

• Armed assailants scaled university walls and opened fire

• Multiple blasts were heard along with continuous heavy gunfire

• 3,000 students enrolled at university

University premises secured

Military spokesperson Lt.Gen Asim Bajwa stated that the university premises has been cleared and four attackers have been killed. Security personnel, including Special Services Group (SSG) personnel were tasked with clearing the university premises and and securing the civilians inside.

The terrorists gave stiff resistance to security forces as they engaged in an operation to clear the school over several hours. Intelligence sources said eight to 10 terrorists were inside the university, adding that they were between 18 and 25 years old, were wearing civilian clothes and had their faces covered.

Snipers had taken position around the premises, with monitoring being provided by aerial assets.

Security forces also cordoned off a one-storey house, situated around a kilometre from the university's boundary wall, where three terrorists were believed to be holed up. It was later declared clear by military personnel.

The families of students lined up outside the school. Most of the boys belonged to Dir, Hangu and other parts of Khyber Pakhtunkhwa province.

Journalists and all other non-essential personnel were asked to stay back in order to not interfere with the ongoing security operation. Up to 20 ambulances entered the university to rescue the injured.

Provincial Minister Shah Farman told journalists 54 security guards were stationed at the university. He said around 200 people were present in the examination hall, all of whom were rescued and "timely action by police and army has prevented large scale damage".

21 killed

“The death toll in the terrorist attack has risen to 21,” regional police chief Saeed Wazir told AFP without specifying if the toll included the four militants the army stated it had killed.

Most of the student victims were shot dead at a hostel for boys on the campus.

The medical superintendent at District Headquarter Hospital, Charsadda confirmed 18 dead. DHQ Charsadda's officials also stated that casualties had cuts on the bodies, probably inflicted from a sharp-edged weapon.

An Edhi volunteer earlier said he had seen the bodies of at least 15 persons.

One Rescue 1122 official said, "The boys section [of the hostel] has been affected. Victims have mostly been hit by bullets."

"Around 90 per cent of the area has been cleared. Over 70 per cent students have been rescued."

Pakistan Tehreek-i-Insaf (PTI) provincial spokesperson Shaukaut Yousafzai said between 50 to 60 people were wounded. He added there was no prior threat about an attack.

Special assistant to chief minister, Mushtaq Ghani said the critically injured victims shifted to the Lady Reading Hospital Peshawar and that security in the province has been on high alert for 10 days.

At least three to four security guards were injured, an eye-witness who managed to come out of the premises said. The Associated Press quoted police as saying gunmen killed an assistant professor and a student in the attack.

DIG Saeed Wazir confirmed that two students and assistant professor Dr Hamid, who taught organic chemistry at the school, have been killed in the attack.

“All students have been evacuated from the hostels, but militants are still hiding in different parts of the university and some students and staff are stuck inside,” Wazir said.

Chief of Army Staff General Raheel Sharif reached Charsadda to boost the morale of the security personnel who took part in the operation. He was accompanied by Corps Commander Peshawar.

Television footage showed soldiers entering the campus as ambulances lined up outside the main gate and anxious parents consoled each other.

Eyewitness: 'The attackers were just like us'

A student speaking to DawnNews said the attackers who has penetrated the building appeared to be young.

"The attackers were like us ─ they were very young. They carried AK-47 guns. They wore jackets like the forces do... We were in the hostel sleeping as we don't have classes.

"There are no classes at the university currently, there may be around 200-300 students in the hostel."

"There was firing between attackers and security forces. After everything was over, the army men knocked on our room and told us we were safe."

Eyewitness: 'I saw a militant firing'

Geology student Zahoor Ahmed said he had tried to leave his hostel after hearing shots fired.

“(We) were stopped by our chemistry lecturer who advised us to go inside.

He was holding a pistol in his hand,” he said.

“Then I saw a bullet hit him. I saw two militants were firing. I ran inside and then managed to flee by jumping over the back wall, “

Eyewitness: 'Attackers took positions'

According to one eyewitness who escaped the university, the attackers had taken position at the entry points of the school. "I saw three attackers engaged in an exchange of fire with security guards of the university. One was positioned at the roof, another near the corner and the third near the wall."

"We rescued the university's guards and then I saw the attackers engage the arriving police party."

Attackers are believed to be on the second and third floors of the campus buildings.

Shabir Khan, a lecturer in the English department, said he was about to leave the hostel for the department when firing began.

“Most of the students and staff were in classes when the firing began,” Khan said. “I have no idea about what's going on but I heard one security official talking on the phone to someone and said many people had been killed and injured.”

Eyewitness: 'My friend was killed'

A student speaking to DawnNews said two security personnel were killed. "A hostel friend of mine was killed, two security personnel were killed as well."

"The gunmen attacked the registrar office. Our professor was killed, his name is Hamid. Some students have also been killed. A friend of mine was so scared he jumped from the university building."

Eyewitness: 'We had no firearms to protect ourselves'

A computer science student who was rescued from the university said the poetry recital event to commemorate Bacha Khan's death anniversary was to begin at 10:30am.

"The university [security] on common days is enough to perplex students. They have five security checks. But the security is only for students and not VIPs," he said.

"In the beginning, there was just firing. There were attackers in the stairwell. We had no arms to counter them."

"In the Pushto Department and Computer Science blocks I saw at least three attackers."

Emergency imposed at hospitals

Rescue officials say some 50 students were rescued from the premises.

Out of these 50, five students were injured and have been shifted to District Headquarters Hospital (DHQ), Charsadda for treatment. An emergency has been imposed in all hospitals of the area.

'University not adequately secured'

An eyewitness rescued from the university said the university was not adequately secured, especially at the backside of the building, which had low boundary walls.

Another eyewitness said that attackers threw a grenade, injuring a guard and then entered the school.

Khyber Pakhtunkhwa's Member of Provincial Assembly Arshad Ali told Dawnnews that the attackers entered the university after scaling its walls.

MPA Fazal Shakoor, who was elected from Charsadda, says army contingents have also arrived at the scene and that firing is continuing.

Former provincial health minister Shaukat Yousafzai speaking at the site said, "This is a frontline province. We are fighting Pakistan's war in this province."

"This is international terrorism. This province is a target of terrorism. We are making full efforts to combat terrorism and it has dropped. The backs of terrorists have been broken and they are breathing their last. This stunt is an attempt to breathe life into their cause."

Eyewitnesses report having heard three blasts inside the university.

The state-run PTV quotes DSP Charsadda as saying that three armed men entered the university premises and opened fire. Television reports added that a large contingent of security forces had reached the site.

Speaking to DawnNews via telephone, a woman inside the university says intense firing is underway. The woman asked for help, saying assistance be sent to the premises.

The attack on the university comes on the death anniversary of Bacha Khan and it began as a mushaira (poetry recitation) was underway at the premises. Around 3,000 students are enrolled at the university.

Vice Chancellor Fazal Rahim told reporters that the university teaches over 3,000 students and was hosting an additional 600 visitors on Wednesday for the recital.

“There are male and female staff members and students on the campus,” Fazal said, adding he had been on his way to work when he was informed of the attack.

Shabir Khan, a lecturer in the English department, said he was about to leave his university housing for the department when firing began.

“Most of the students and staff were in classes when the firing began,” Khan said. “I have no idea about what's going on but I heard one security official talking on the phone to someone and said many people had been killed and injured.”

Security forces had earlier conducted search operations in adjoining areas and claimed that four wanted men had been arrested. Weapons and army and police uniforms were also recovered from the arrested men.

Read: Peshawar schools closed after terrorist attack rumours

Charsadda is a district in Pakistan’s northwestern province of Khyber Pakhtunkhwa and has been a scene of several militant attacks during the past decade. The region is mostly rural in its makeup and lies 40 kilometres from Peshawar.

2011-15: Attacks on educational institutions in Pakistan

Condemnations pour in

Prime Minister Nawaz Sharif in a statement issued from Zurich said he is "deeply grieved" over the attack at the university.

"Those killing innocent students and citizens have no faith and religion," the statement said. "We are determined and resolved in our commitment to wipe out the menace of terrorism from our homeland."

The premier has also announced a national day of mourning tomorrow (Jan 21), and the national flag would be lowered to half-mast.

The prime minister is in Switzerland to attend the World Economic Forum.

Pakistan Tehreek-i-Insaf Chairman Imran Khan said, "I will visit Charsadda and the attack site to review the situation. I will review if we are at fault or not."

"We are all on the same page, the whole nation stood united after the APS attack."

The PTI chairman added that they have also asked KP Chief Minister Pervez Khattak to return as soon as possible from England.

Indian Prime Minister Narendra Modi condemned the attack and offered his condolences to the families of the deceased.

Attack was feared

Rumours of possible terrorist attacks on schools had been circulating in Peshawar and surrounding rural areas over the last week, forcing some schools to close educational institutions early.

District administration had directed some schools to close their campuses for one day (last Saturday) insisting there were reports of possible terrorist attacks on them.

Video updates

Pakistan Army soldiers reach the university where the attack is underway and a number of staff and students are believed to be held hostage

A telephone operator with the university who was rescued by security forces speaks to the media.

An eye-witness told DawnNews the firing began around 9:15 am and attackers managed to enter the premises of the university from the back walls.

A rescue official told DawnNews ambulances under police and army supervision were engaged in rescuing people inside the varsity.

PTI provincial spokesperson Shaukaut Yousafzai said 'terrorists are breathing their last and wanted to pull something in their last days'

Asfandyar Wali, who is a grandson of Bacha Khan, said it was condemndable that despite the National Action Plan (NAP), little came about in terms of curbing terrorism.

Chief of Army Staff General Raheel Sharif arrives at the Bacha Khan University

─ Additional reporting by Mateen Haider.