Three security personnel were killed and eight persons injured when a powerful explosion ripped through a security forces vehicle in the Pakistani port city of Karachi on Wednesday.
The explosion occurred near an office of the Pakistan Rangers at Korangi area of Karachi at about 7.30 pm.
Three Pakistan Rangers personnel died in the attack, security officials told the media.
Five security personnel and three passers-by were injured, officials and witnesses said.
A security forces van was destroyed by the blast.
Deputy Inspector General of Police Tahir Naveed told media persons that the blast had targeted the security forces vehicle.
He said the attack could have been carried out in retaliation to an operation launched by security forces against criminals and militants in Karachi.
Footage on television showed the body of one paramilitary personnel, covered with a white sheet, lying on a stretcher outside the state-run Jinnah Hospital.
Officials at the hospital said two of the wounded were in a serious condition.
No group claimed responsibility for the attack.
Over the past few days, the Pakistan Rangers and police have targeted members of the Taliban and other banned groups in several parts of Karachi, the country's largest city.
Security personnel arrested several militants and seized sophisticated weapons and explosives during the crackdown.