Osama bin Laden's killing brought to an end the most intense manhunt in history and as the four helicopters swooped down on the isolated villa, bin Laden's Arab bodyguards opened fire from the roof of the house.
An intense round of heavy gunfire rocked Abbottabad as the fighting raged in the town, which is home to three Pakistani army regiment and is dotted with military buildings.
US officials, who did not want to be named, said the discovery that bin Laden was holed up in an army town in Pakistan raised pointed questions about how he managed to evade capture and whether Pakistan's military intelligence knew about his whereabouts and sheltered him.
Most intelligence estimates figured that bin Laden was holed up in Pakistan's tribal areas, close to the Afghan border, possibly in a cave sheltered by loyal tribesmen.
US officials said it was not immediately known how long bin Laden had been in Abbottabad, which is just an-hour-and-half drive from Islamabad.
A Pakistani official claimed the helicopters took off from the Ghazi Air Base in northwest Pakistan where the US army was based to help out in the aftermath of the floods in 2010.
ABC quoted Pakistani officials as saying that a son of bin Laden and three others were killed in the raid. There was no US casualty.
The reports said that a number of heavily armed men, apparently bin Laden''s bodyguards, were taken away from the scene by the US forces.
The house were Osama was holed is just 100 yards from the gate of the Kakul Military Academy, an army run institution where top officers train.
Giving a graphic account of the operation, ABC quoting officials said some 10 years after the abortive US bid to nab him in the caves of Tora Bora, a small group of American forces in helicopters took just 40 minutes to land in a well-guarded mansion in a secure neighbourhood.
Disgorging from choppers, the commandos shot Osama in his head after some fire exchange, officials said.
Noting that the operation itself was a culmination of years of careful and highly advanced intelligence work, a senior administration official said officers from the CIA, National Security Council and other intelligence wings of the government world very hard to get every possible information about the most wanted fugitive of the world.
According to sources, a small US team conducted a helicopter raid on the compound early Pakistan morning.
"This operation was a surgical raid by a small team designed to minimize collateral damage and to pose as little risk as possible to non-combatants on the compound or to Pakistani civilians in the neighborhood," the official said.
The US team was on the compound for under 40 minutes and did not encounter any local authorities while performing the raid. In addition to Osama bin Laden, three adult males were killed in the raid.
Authorities believe that two were the couriers and the third was bin Laden's adult son. There were several women and children at the compound.
One woman was killed when she was used as a shield by a male combatant. Two other women were injured. During the raid, one helicopter was lost due to mechanical failure.
The aircraft was destroyed by the crew and the assault force and crew members boarded the remaining aircraft to exit the compound. All non-combatants were moved safely away from the compound before the detonation.