PESHAWAR: At least 21 people were killed and 50 others injured during a gun and bomb attack at an imambargah in Peshawar's Hayatabad area when suicide attackers and gunmen — dressed in police uniforms — attacked worshippers offering Friday prayers.

Khyber Pakhtunkhwa Information Minister Mushtaq Ghani confirmed the death toll and called for the deployment of Frontier Corps personnel, saying the imambargah is very close to tribal areas which allows easy access for terrorists.

Banned militant organisation Jundullah, a splinter group of Tehreek-i-Taliban Pakistan (TTP), claimed responsibility for the terrorist attack through an email statement later in the evening, saying it was revenge for a militant known as Doctor Usman — who was hanged in December.

“This is a series of taking blood for blood, which will continue. The government should expect more and even harder responses,” the statement said. The proscribed group also posted a photograph of what it claims are the attackers involved in Friday’s carnage.

Eyewitnesses and sources said that the attack took place when the worshippers were offering prayers in the mosque situated inside the imambargah.

Heavy firing was also reported and residents said a thick cloud of smoke engulfed Hayatabad's Phase V area soon after the attack. They said three explosions took place inside the mosque of the Imamia Imambargah at the time of Friday prayers.

Eyewitnesses claim that three more attackers, in addition to the three suicide bombers, had entered the imambargah after scaling the neighbouring Allama Iqbal University’s wall. They feared that the three men may have fled the place of worship soon after carrying out the attack.

Khyber Pakhtunkhwa Inspector General Nasir Durrani said attackers did not enter the imambargah through the main gate as security personnel were deployed there.

SSP operations Dr Mian Saeed said three suicide bombers entered the mosque while only one was able to blow himself up. Another suicide bomber was killed by security forces while the third was arrested in injured condition.

An eyewitness told Dawn that Friday prayers were being offered at the mosque when five to six armed men wearing security forces' uniform entered the place of worship and hurled grenades at the security personnel deputed at the premises.

He added that one of the attackers, wearing a suicide vest, blew himself up inside the imambargah when the worshippers tried to wrestle and snatch the weapons of the attackers. After the suicide blast the rest of the attackers began indiscriminate firing.

The police and army personnel conducted a joint operation and cordoned off the area after which bomb disposal squad searched the blast site and defused the suicide jackets and grenades recovered from the attackers.

Hayatabad was under heavy surveillance as helicopters hovered over the area and dozens of FC troops took position to clear the vicinity.

The attack comes two weeks after a suicide bombing at an Imambargah in Shikarpur which killed 61 people — the deadliest sectarian incident to hit the country in nearly two years.

Read: At least 60 killed in blast at Shikarpur imambargah

Three day mourning announced

Majlis Wahdatul Muslimeen (MWM), Shia Ulema Council, Jaffria Alliance and Imamia Rabita Council have announced to observe three-day country-wide mourning.

Political leaders including Pakistan Tehreek-i-Insaf Chairman Imran Khan, Jamaat-i-Islami (JI) leader Sirajul Haq and Muttahida Qaumi Movement chief Altaf Hussain condemned the attack on the Imambargah in Peshawar. Prime Minister Nawaz Sharif and President Mamnoon Hussain also denounced the attack in strong words.

Imran Khan strongly condemned the terror attack and said he tried to visit to blast site but was stopped due to ongoing security operation.

Shia scholar Arif Hussain condemned the attack, adding that these attacks will continue if they are not brought under control. "They are enemies of the state and Islam," he said.

Appeal for blood donations were made at hospitals in Peshawar as casualties rose and some injured battled for their lives. Officials say due to the large number of injuries, a lack of space was reported at the Hayatabad Medical Complex, with the injured being shifted to other hospitals.

Families were also seen flocking to the Hayatabad Medical Complex to look for their family members injured in the attack.

The blast on Peshawar's imambargah comes as Pakistan is attempting to implement the National Action Plan to combat and root out terrorism from the country, an initiative that was set in motion after the December 16 attack at Peshawar’s Army Public School.

At the same time, Pakistani security forces are engaged in the North Waziristan and Khyber tribal regions — with the operation in Waziristan starting soon after a terrorist attack on Karachi's Jinnah International Airport.