At least four people, including three Chinese nationals, were killed while four others were injured in a suicide attack outside the University of Karachi's (KU) Confucius Institute, officials said on Tuesday.

The incident happened as a van, carrying staff members, was about to enter the Confucius Institute, located next to the commerce department.

Television footage showed a white van in flames with plumes of smoke rising from its remains. The windows of nearby buildings were also seen shattered from the impact of the explosion.

CCTV footage of the attack showed a burqa-clad woman standing outside the entrance of the Confucius Institute. The woman detonated herself just as the van neared the institute's entrance.

Sindh Inspector General of Police (IGP) Mushtaq Ahmed Mahar confirmed that four people had died. A handout from Sindh Chief Minister Murad Ali Shah’s office quoted the IGP as saying that the blast took place at approximately 2:30pm.

The banned Baloch Liberation Army (BLA) claimed responsibility for the attack.

A spokesperson for the university confirmed that three of the victims were Chinese nationals. They were identified as Confucius Institute Director Huang Guiping, Ding Mupeng and Chen Sai. The fourth victim was the van’s driver, Khalid.

The spokesperson also identified two of the injured as Wang Yuqing, a Chinese faculty member, and Hamid.

"Academic activities and public dealings will remain suspended at KU on Wednesday (tomorrow) to mourn the loss of the Confucius Institute's faculty members," the spokesperson said.

Earlier in the day, SSP East Syed Abdul Rahim Sherazi had hinted that a "couple" of Chinese nationals, who were part of KU faculty, were among the deceased.

Ball bearings found

Counter-Terrorism Department (CTD) official Raja Umar Khattab said that the suicide attack was carried out by a woman, adding that ball bearings were found at the site of the blast.

He said the van was properly guarded as a Rangers team was escorting it which was why an improvised explosive device (IED) was not used.

Responding to a question, the CTD official said he did not believe a security lapse was the reason behind the attack since thousands of students were coming and going out of the university and checking each of them was a problem.

Karachi police chief Ghulam Nabi Memon said that it was unfortunate that teachers had been targeted. Speaking to the media, he said that four others had been injured, including a Chinese national, a private security guard and a Rangers personnel.

Memon said that a Rangers team was accompanying the Chinese nationals. Asked whether a threat had been issued prior to the attack, the senior officer said that there was "always a threat".

He said tight security arrangements were already in place at the varsity, adding that any lapses would be "revisited". "Give us time to look at the CCTV footage and interview witnesses," he said.

Speaking to the media earlier, DIG East Muqaddas Haider said initial information showed the van was headed to the institute after leaving the hostel.

"The explosion took place at the van's right side at the [institute's] entrance," Haider said, confirming that four people had been killed.

'Cowardly incident direct attack on Pak-China ties'

Later in the day, the Foreign Office (FO) issued a statement condemning the "reprehensible terrorist attack".

In a statement, FO spokesperson Asim Iftikhar said the government and the people of Pakistan extend their deepest condolences and sympathies to the families of the victims.

"The law enforcement agencies are investigating the incident to apprehend the culprits and bring them to justice. Local authorities are also providing all possible assistance to the injured," he said.

The FO spokesperson termed the incident a "direct attack on the Pakistan-China friendship and ongoing cooperation".

Calling the two countries "close friends" and "iron brothers", he said Pakistan attached great importance to the safety and security of Chinese nationals, projects and institutions in the country.

'Amazing teacher'

Mustajab Hussain, a 25-year-old student hailing from Gilgit-Baltistan, was heartbroken over the death of one of his teachers.

Hussain, who has been studying at the Confucius Institute for the past three years, said that two female faculty members were among the deceased while the third one was the director, based on the identities shared by the KU spokesperson. The director had just come around a month ago.

“Chen Sai was my teacher. Her class was at 2:30pm. She was an amazing teacher and very friendly. Whatever we found difficult, she would always explain very nicely. She was very young, in her early 20s," he said.

According to Hussain, the Chinese faculty members used to live at a guest house inside the KU premises. They were coming from the guest house to the institute when the explosion occurred at the gate.

Sindh CM visits Chinese consulate

Meanwhile, the Sindh chief minister paid a visit to the Chinese Consulate where he briefed Consul General Li Bijian about the blast.

Shah expressed grief over the death of the Chinese nationals, a statement issued by the CM's office said. The chief minister also assured the Chinese official that the incident would be fully investigated, the statement added.

"Those involved in the incident will be brought to justice. We value the services rendered by Chinese experts in the country and the province," Shah said.

"Some elements do not like the partnership between the two countries," he said, adding that the miscreants behind the incident would be dealt with an iron hand.

Separately, Prime Minister Shehbaz Sharif expressed grief over the blast in a telephone call with the Sindh chief minister. The premier assured Shah of the Centre's full help and cooperation in dealing with such incidents.

Condemnations

According to the Prime Minister's Office (PMO), PM Shehbaz called Shah to collect information about the "terrorist incident".

"The prime minister said that terrorists are [the] enemies of Pakistan. He vowed to eliminate the remainder of terrorists through collective efforts and unity. He directed for the provision of the best medical facilities to the injured," the PMO said.

The prime minister also issued a statement on Twitter, saying that he was "deeply grieved" over the loss of precious lives and termed it a "heinous attack".

"My heartfelt condolences go to the bereaved families. I strongly condemn this cowardly act of terrorism. The perpetrators will surely be brought to justice," he said.

PTI leader Asad Umar said the attack was "yet another attempt to derail the China-Pakistan Economic Corridor (CPEC) and sabotage the economic development of Pakistan."

"The whole nation should be united in its resolve to defeat the aims of these anti-Pakistan hostile forces," he said.

PPP Chairman Bilawal Bhutto-Zardari also condemned the attack and prayed for the lives lost. "Sindh police will soon get to the bottom of the incident," he said, adding that the perpetrators would be punished.

He called for steps to be taken to ensure the safety of Chinese citizens.

Additional input by Naveed Siddiqui