US officials said bin Laden was found in a million-dollar compound in the upscale town of Abbottabad, 60 km north of the Pakistani capital Islamabad. A source familiar with the operation said bin Laden was shot in the head.

"Justice has been done," President Barack Obama declared in a hastily called, late-night White House speech announcing the death of the elusive head of the militant Islamic group behind a series of deadly bombings across the world.

Leaders worldwide praised the killing as a dramatic success in the war against al Qaeda, although many analysts cautioned it was too soon to say bin Laden's death would mark a turning point in the battle against a highly fractured network of militants.

Jubilant, flag-waving celebrations erupted in Washington and New York after Obama's announcement. It was the biggest national security victory for the president since he took office in early 2009 and could give him a political boost as he seeks re-election in 2012.

Obama may now also find it easier to wind down the nearly decade-old war in Afghanistan, begun after the September 11, 2001, attacks on New York and Washington that killed nearly 3,000.

But the operation could complicate relations with Pakistan, already frayed over US drone strikes in the west of the country and the jailing of a CIA contractor accused of killing two Pakistani men.

A US official said Pakistani authorities were told the details of the raid after it had taken place.

The revelation bin Laden was living in style in a mansion will also put Pakistani officials under pressure to explain how he could have been right under their noses. Residents in Abbottabad said a Pakistani military training academy is near the compound.

"For some time there will be a lot of tension between Washington and Islamabad because bin Laden seems to have been living here close to Islamabad," said Imtiaz Gul, a Pakistani security analyst.

US officials said American forces were led to the fortress-like three-story building in Abbottabad after more than four years tracking one of bin Laden's most trusted couriers, whom US officials said was identified by men captured after the September 11, 2001 attacks.

"Detainees also identified this man as one of the few al Qaeda couriers trusted by bin Laden. They indicated he might be living with or protected by bin Laden," a senior administration official said in a briefing for reporters in Washington.

Bin Laden was finally found after authorities discovered in August 2010 that the courier lived with his brother and their families in an unusual and extremely high-security building in Pakistan, officials said.

"When we saw the compound where the brothers lived, we were shocked by what we saw: an extraordinarily unique compound," a senior administration official said.

"The bottom line of our collection and our analysis was that we had high confidence that the compound harbored a high-value terrorist target. The experts who worked this issue for years assessed that there was a strong probability that the terrorist who was hiding there was Osama bin Laden," another administration official said.

Bin Laden and three adult men, including a son of bin Laden, were killed along with a woman who was used as a shield by a male combatant, officials said.

The New York Times said bin Laden's body was taken to Afghanistan and then buried at sea.