ISLAMABAD/WASHINGTON: World’s most dreaded terrorist Osama bin Laden was shot dead Monday in a pre-dawn helicopter-borne secret US operation in a house just yards away from Pakistan’s Military Academy in Abbottabad, raising questions whether the establishment knowingly harboured him.

Four US helicopters carrying special forces personnel swooped down on a million dollar compound near an upscale town, 120 km north of Pakistani capital Islamabad, and shot dead the 54-year-old al-Qaeda chief in a swift operation which lasted only 40 minutes. The operation climaxed an almost 10-year long massive worldwide manhunt for the man, who US believes is the mastermind of the 2001 9/11 attacks.

The world’s most wanted terrorist was found living in a fortress-like two-storey house in Abbottabad, almost next door to Pakistan’s Kakul Military Academy, which is home to army’s three regiments and far away from remote mountain caves where most intelligence estimates put him in recent years.

"The compound was custom-built to hide someone of significance," US officials said after the raid, as army commandos stormed the bastion shooting down bin Laden in the head and face. His death was reported to be instantaneous as he got into a firefight with heavily-armed commandos. Their helicopters were fired upon by bin Laden’s ultra loyal Arab bodyguards.

The news of the slaying of the world’s most prominent terror mastermind was broken to the world by US President Mr Barack Obama, who made the announcement live from White House. "Bin Laden, 54, is dead and his body is in US custody," Mr Obama said at half past 11 midnight US time after initial story had been broken by news channels. Though it was dark, crowds massed outside White House chanted ‘USA, USA.’

Besides the al-Qaeda chief, who carried a bounty of US$ 25 million, two couriers, one of whom was his son and the other a woman, reportedly used as a human shield, were killed in the operation, US officials said, adding it was through these couriers that bin Laden had been traced.

The US special forces flew away bin Laden’s Arab bodyguards while women and children present in the compound were not harmed, officials said. Hours after they had shot him down, US officials said bin Laden was buried at sea.

The presence of bin Laden in Pakistan, which it had always denied, goes to the root of the problem of mistrust US always had over the last 10 years with its key ally, the Pakistani military and its powerful spy agency ISI. More so when Osama was traced to a secret mansion guarded by Arabs close to a prestigious Pakistani military establishment giving rise to doubts whether he was sheltered. The US did not notify its ally Pakistan about the operation, citing maintaining complete secrecy as the reason.