A group of heavily armed militants stormed a military airbase, PNS Mehra, in the Pakistani port city of Karachi early Monday morning, killing five security personnel and injuring many.

According to various media reports, three militants were killed and four have been arrested.

About 12 to 15 militants targeted PNS Mehran, the naval air station within Faisal airbase, at about 10.40 p.m. last night.

Naval spokesman Mr Irfan-ul-Haq told the media that four naval personnel and a paramilitary trooper were killed and nine more naval personnel injured in running gun battles with the terrorists.

Reports say that four navy and one ranger personnel have been killed and fourteen injured. Pakistan Interior Minister Rehman Malik said: This is a terrorist attack. We condemn the attack in which four navy officers have been killed and three rangers are injured. Search operations are on and ambulances have reached the location.

Geo News reports said that one person has been detained from the spot.

The banned Tehrik-i-Taliban Pakistan and Baloch separatists have claimed the responsibility the brazen attack on the base by 15-20 gunmen, saying it was to avenge the killing of al Qaeda leader Osama bin Laden on May 2. It was the revenge of martyrdom of Osama bin Laden. It was the proof that we are still united and powerful, Ehsanullah Ehsan told Reuters by telephone from an undisclosed location.