Pakistan army's elite Special Service Group and naval commandos backed by helicopters were hunting down a group of 15-20 militants, who stormed into the sprawling naval complex last night in the worst assault on a military base since the Army Headquarters was besieged in October 2009 in Rawalpindi.

The terrorists in a well coordinated attack sneaked into the complex, reportedly housing US-acquired P-3C Orions, long-range maritime reconnaissance planes and Harpoon anti-ship missiles and were locked in continuing gun battle with the security forces.
Eleven naval personnel, including a lieutenant, and two paramilitary troopers were killed till noon today, naval spokesman Irfan-ul-Haq told the media.

Fourteen security personnel - including 11 from the navy - were injured in the skirmishes with the terrorists, he said.

Tehreek-e-Taliban Pakistan claimed responsibility for the attack, saying it was part of revenge for the May 2 American raid that killed al-Qaeda chief Osama bin Laden and that their men had orders to fight till death.

"They do not want to come out alive. They have gone there to embrace martyrdom," Taliban spokesman Ehsanullah Ehsan told foreign agencies from an undisclosed location in northwest Pakistan.

There were unconfirmed reports that four terrorists were killed or had blown themselves up while another four were captured by security forces.

Spokesman Haq did not give details of casualties among the attackers, saying the operation to flush them out was still underway. Some of the arrested terrorists had identity cards of security agencies, Geo News channel reported.

Local television news networks aired images of an aircraft caught in flames and thick smoke billowing out of the naval base as staccato of gunfire echoed from the background.

New York Times reported that Mehran, while an important base, is far from the most vital military installation in the teeming port city. About 15 miles away is the Masroor airbase of the PAF which is believed to be a large depot for nuclear weapons that can be delivered from the air.

Over 20 loud explosions were heard from the base, the headquarters of Pakistan's naval air arm, following the attack and intermittent firing was reported till this morning.Interior Minister Rehman Malik, who was dispatched to Karachi by Prime Minister Yousuf Raza Gilani to monitor the situation, said the terrorists entered the airbase from three directions.

"A building in the premises is still under their control from where they are exchanging fire with soldiers," he said.

"The situation is being tackled delicately to secure assets, minimise human losses and defeat the terrorists completely," he said, adding, "It is not just an attack on a navy establishment, it is an attack on Pakistan."

Hundreds of security personnel, including paramilitary Pakistan Rangers and elite naval and army commandos, moved into the airbase to flush out the terrorists.

Authorities used helicopters to mount surveillance over the airbase after dawn.
Heavy exchanges of fire between the attackers and terrorists continued till about 11.30 pm last night, and were followed by intermittent firing and over 20 blasts.

The high-security area where the attack occurred houses the PAF's Southern Air Command, Air War College and museum as well as PNS Mehran, the main naval air station in Karachi.

Security was tightened across Pakistan following the attack, particularly at military installations and in the federal and provincial capitals.President Asif Ali Zardari and Prime Minister Yousuf Raza Gilani strongly condemned the terrorist attack.

Gilani said such "cowardly acts of terror could not deter the commitment of the government and people of Pakistan to fight terrorism"