Al-Qaeda mastermind Osama bin Laden was killed Sunday in a daring raid by US covert forces in Pakistan, and President Barack Obama declared "justice has been done" a decade after the September 11 attacks.
The death of the reviled US enemy, after a huge manhunt, sparked an explosion of joy across the United States, especially in New York and Washington, the targets of the worst-ever attack against the US mainland in 2001.
Bin Laden's demise also marked the biggest triumph yet in the 10-year war against terrorism, which has led the United States into two bloody wars, transformed its foreign policy and reshaped many aspects of American life.
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"Tonight, I can report to the American people and to the world that the United States has conducted an operation that killed Osama bin Laden, the leader of Al-Qaeda, and a terrorist who's responsible for the murder of thousands of innocent men, women and children," Obama said in a dramatic late night address.
Obama said he had directed helicopter-borne US armed forces to launch an attack against a heavily fortified compound in Abbottabad, Pakistan on Sunday acting on a lead that first emerged last August.
"A small team of Americans carried out the operation with extraordinary courage and capability. No Americans were harmed. They took care to avoid civilian casualties," Obama said.
"After a firefight, they killed Osama bin Laden and took custody of his body."
"Justice has been done."
Senior US officials said that in addition to bin Laden, three adult males died in the raid, two who were believed to be couriers for the Al-Qaeda leader, and one who was said to be one of his adult sons.
One woman who was being used as a human shield was also killed, the officials said.
American forces lost a helicopter in the operation due to "mechanical failure" and the chopper was destroyed by the Americans, the official said.
Other US officials said they were stunned when intelligence reports first revealed the elaborate security at the compound where bin Laden was hiding, with 12-18 foot (four-to-six meter) high walls topped with barbed wire.
A key to the operation was a long-running effort by American spy agencies to track a trusted courier for bin Laden, another senior US official said.
The operation will also likely go down as one of the most spectacular intelligence operations in US history, and provide a huge morale boost for the oft-criticized US clandestine community.
It marks a rare moment of national celebration, after grim years of war abroad and as America only slowly emerge from the worst recession in decades.
The huge coup may also enhance perceptions of Obama's leadership and help turn around his political fortunes a year ahead of his reelection bid.
Former US president George W. Bush, who was in office at the time of the September 11 attacks when almost 3,000 people died, said bin Laden's death was a "momentous" event and congratulated Obama and US intelligence and military forces.
"This momentous achievement marks a victory for America, for people who seek peace around the world, and for all those who lost loved ones on September 11, 2001," he said in a statement.
"The fight against terror goes on, but tonight America has sent an unmistakable message: No matter how long it takes, justice will be done."
Outside the White House, thousands gathered outside the gates of the White House, cheering, waving US flags and shouting "USA, USA."
Another large crowd gathered at the "Ground Zero" epicenter of the World Trade Center attack, singing "God Bless America."
Tourists and New Yorkers also descended on Times Square.
"It's a miracle," said New Yorker Monica King, 22. "The attacks changed New York and now 10 years later we had our last word," she added, saying: "Now we want to celebrate."
Gary Talafuse, visiting from Texas, said Americans "feel a lot of national pride."