Balochistan's Parliamentary Secretary for Information Bushra Rind on Thursday said the detained husband of the alleged Karachi University suicide bomber claims his wife was "mentally ill".

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 Confucius Institute two days ago.

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.

The banned Baloch Liberation Army had later claimed responsibility for the attack.

Investigators identified the bomber as Shari Baloch, a married mother of two. On Wednesday, CTD official Raja Umar Khattab said that her husband, who he identified as Dr Haibatan, was missing and that raids were being carried out to find him and other facilitators.

Addressing a press conference in Quetta today, Rind confirmed that the husband had been arrested by law enforcement and that he made the revelation of his wife's mental state in the course of interrogation.

She quoted the husband as saying his wife was receiving medication for her mental illness.

Rind said "external forces" were attempting to involve Baloch people in anti-national activities in a "cowardly attempt" to discredit and portray the community in a bad light. "The Baloch nation won't be affected by such hostile conspiracies," she vowed.

She said the suicide blast was a "tragic incident" targeting Chinese teachers and strongly condemned the attack.

A day ago, Balochistan Chief Minister Mir Abdul Qudoos Bizenjo, in a video message, had said targeting Chinese teachers in Karachi University was "highly reprehensible" and against Baloch tradition. "This is the first time we have seen such an event," he added.

Bizenjo said the nation would emerge victorious in its fight against terrorism.