The Pakistani Taliban claimed responsibility on Monday for a blatant attack on a Karachi naval base that killed 5 people and destroyed a naval aircraft, saying that the attack was a retaliation for the death of Osama bin Laden.

It was the revenge of martyrdom of Osama bin Laden. It was theproof that we are still united and powerful, Ehsanullah Ehsan told Reuters by telephone from an undisclosed location.

Three more explosions have been heard from the base where more than a dozen militants holed up, after storming the installation with guns and grenades on Sunday night, killing at least five people and destroying a military aircraft, reported Reuters.

The bomb blast that rocked the PNS Mehran naval base in the southern city of Karachi, brought back the memories of an assault on Pakistan's army headquarters in the town of Rawalpindi in 2009, and also raised questions on security of the naval base, which was one of the country's most well-guarded installations.

Nine explosions were reported from the base on Sunday night and eleven people suffered wounds in an attack on the country's most well guarded installations. Jet fuel tanks have also reported to have caught fire and exploded.

The assault took around four hours before most of the fire could be extinguished and the shooting had reduced.

Terrorists are still there and putting up resistance, Navy spokesman Mohammad Yasir reported Reuters.

The dead included one sailor, three firefighters and an Army ranger, he added.

The operation still continues. It is not over yet, said one security official.  As dawn broke over the base, renewed gunshots could be heard as well as three loud blasts.