NEW YORK - Al-Qaeda militants, who tried to hijack a Pakistan Navy frigate earlier this month, intended to use it to target US Navy vessels on anti-terrorism patrol in the northwestern Indian Ocean, The Wall Street Journal reported on Wednesday, citing Pakistani security officials.

The Sept 6 raid, which was foiled after a firefight and a suicide bombing, was carried out in part by Pakistan Navy personnel who had been recruited by Al-Qaeda, the report said, adding it raised fears about terrorist infiltration of the nuclear-armed nation’s military forces.

Describing the Karachi raid as the first major operation carried out by the Al-Qaeda’s newly formed regional wing, the Journal said its timing may have been set to mark the start of the affiliate or to coincide roughly with the anniversary of the Sept 11, 2001 attacks.

News of the attempted seizure of the frigate, PNS Zulfiqar, the report said was initially kept from the media, and the details of the incident are only beginning to emerge.

It was pointed out that the Pakistan Navy works closely with the US Navy and other foreign maritime forces in combating terrorism, piracy and the drug trade in the Indian Ocean. That cooperation includes the docking of ships from allied nations in Karachi.

“If we are to work with the Pakistan Navy, we have to be able to trust them. This attack raises a lot of questions,” an unnamed Western counterterrorism official was quoted as saying.

The Karachi plot has drawn comparison with the October 2000 attack on US Navy destroyer USS Cole by Al-Qaeda in the Yemeni port of Aden, in which 17 US sailors died.

“The Pakistan Navy very bravely thwarted this attack. There was no damage of any kind to our installations,” Defence Minister Khawaja Asif said.

A US official was quoted as stating that although Al-Qaeda does recruit within the Pakistani military, but “these occurrences are rare.”

Still, there have been several attacks on military facilities and personnel in Pakistan carried out with the help of serving and retired military, it was pointed out.

In the attempted seizure of PNS Zulfiqar, “the rogue officers were in uniform and had their service cards displayed. They simply walked on board,” one Pakistani security official said.

Pakistani officials said the frigate was due to sail the same day to join an international naval flotilla in the Indian Ocean. On Aug 15, Pakistan took over from Britain’s Royal Navy the command of Combined Task Force-150, a multinational maritime security coalition that includes the US and is focused on combating terrorism.

“It appears the officers on board were to be joined by other militants who were to arrive by boat from the sea and then stow away on board,” the Pakistani security official said.

“The plan was to get close to the US ships on the high seas, and then turn the shipboard weapon systems on the Americans.”

The frigate’s weaponry includes an anti-ship missile system with a range of up to 300 kilometres.

The militants plan was foiled primarily by the alertness of PNS Zulfiqar’s gunner, the Journal said. His vigilance was probably sharpened, Pakistani officials said, by the security precautions implemented since recent intelligence led to the arrest of a gang of Uzbek militants planning an attack on Pakistan Navy facilities. Official maps and details of naval facilities were also found on militants captured in Waziristan on the Afghan border four days before the Karachi attack.

The militants who were supposed to board PNS Zulfiqar approached the docked ship in an inflatable boat, wearing Marine uniforms.

“The gunner felt they were too close and their weapons appeared to be AK-47s, which aren’t standard Marine issue,” a Pakistani security official said.

“The gunner turned his sights on them and fired a warning shot. The militants, fearing the game was up, also retaliated with rockets and automatic weapons.”

At the sound of the firing, Marines and naval commandos rushed to the ship and were engaged by the renegade officers awaiting the militants on the inflatable boat, the report said.

While those on board the ship continued to fight it out for a few hours, the ones in the inflatable boat had no chance, security officials said.

The gunner ripped apart the boat with his Gatling antiaircraft gun, killing all six in the boat.

The four rogue naval men were killed aboard the frigate, officials said. The battle ended when the last surviving rogue naval officer — a young Navy sub-lieutenant — blew himself up after being surrounded.

Pakistani military officials are divided over how much damage could have been accomplished. “Taking over an attack frigate is not a joke, as measures are already in place to face eventualities such as mutiny,” one official was quoted as stating.

Among those killed on the inflatable boat was former Pakistan Navy Lt Owais Jakhrani.

Officials said he had been recently dismissed for harbouring extremist views.

He was the son of a serving Karachi Police Superintendent, and Pakistani intelligence officials believe he played the key role in recruiting naval personnel to Al-Qaeda.

Four other people involved in the attack were later arrested, Pakistan officials stated.

“I can neither confirm nor deny the involvement of naval officials,” Pakistan Navy’s spokesman Commodore Nadeem Bokhari was quoted as saying. “All I can say is that four of the attackers were arrested, the attack was successfully prevented and investigations into it are continuing.”

Al-Qaeda’s claim of responsibility includes a photo of what it stated are the target US ships — possibly taken earlier by one of the renegade Pakistani naval officers, the report said. Al-Qaeda’s statement also included a diagram of the layout of PNS Zulfiqar.

A Western counterterrorism official said the intended target could have been an American naval supply ship deployed in the Indian Ocean. “If they hadn’t been detected, the minimal damage would have been similar to the USS Cole in 2000. However, if they had somehow managed to manoeuvre the weapons systems, then we are talking about a full-scale naval engagement,” another Pakistani security official was quoted as stating.

The attempted strike was initially claimed by the Pakistani Taliban, which works closely with the Al-Qaeda. Then, on Sept 10, the new Al-Qaeda in the Indian Subcontinent issued its own claim.

“The naval officers who had captured the PNS Zulfiqar intended to use it to attack American ships and Marines,” said the AQIS statement. “They were ready to render any sacrifice, including carrying out a martyrdom operation and were only prevented by bombardment by the Pakistani Navy.”

Following the Sept 6 raid, three naval officials were arrested in Quetta near the Afghan border.