|Witnesses in Abbottabad described hearing helicopters, a gun battle, and explosions [Al Jazeera]
The US president has said the world is better and safer after the death of al-Qaeda leader Osama bin Laden.
Speaking at the White House on Monday, Barack Obama said bin Laden's death showed that the US had kept its commitment to seeing that justice was done.
Obama also praised the people gathered spontaneously at the White House and in New York to celebrate bin Laden's death, saying that embodied the true spirit and patriotism of America.
He plans to visit New York on Thursday to honour victims of the September 11, 2001 attack on the city and meet with the families of those killed.
Bin Laden claimed responsibility for planning the September 11 attacks on New York and Washington.
Bin Laden, the most-wanted fugitive on the US list, was killed in a firefight with American forces in Pakistan and quickly buried at sea.
Long believed to be hiding in the mountainous tribal region between Pakistan and Afghanistan, bin Laden was tracked down to a custom-built mansion in the town of Abbottabad, 61km north of the capital Islamabad.
Confronted by US special forces who were dropped by helicopter into the compound, bin Laden was shot dead in a 40-minute operation under the cover of night, US officials said.
Crowds gathered to celebrate outside the White House in Washington, DC, as well as in New York City - one of the sites of the September 11 attacks.
A resident of Abbottabad recounts witnessing the US raid on bin Laden's mansion in the Pakistani city
But celebrations over the operation were tempered by fears of retaliation, and the US quickly issued security warnings to Americans worldwide.
"A small team of Americans carried out the operation with extraordinary courage and capability," Obama said. "After a firefight, they killed Osama bin Laden and took custody of his body."
Four people, including one of bin Laden's sons, were also killed in the operation, US officials said.
After the firefight, US officials said they used "multiple methods" to positively identify bin Laden's remains.
US officials said later on Monday that DNA tests confirmed the death, providing a match with 99.9 per cent confidence.
The US is believed to have collected DNA samples from bin Laden family members in the years since the September 11, 2001, attacks that triggered the US-led invasion of Afghanistan.
Buried at sea
Officials said bin Laden's body was quickly buried at sea, adhering to Islamic procedures including washing the corpse.
It was placed in a "weighted bag," an officer made some religious remarks and the remains were put on a flat board and tipped into the North Arabian Sea off the aircraft carrier USS Carl Vinson, Pentagon officials said.
"We wanted to avoid a situation where it would become a shrine," the AFP news agency quoted one official as saying.
Dr Ahmed El-Tayeb, the head of al-Azhar, Egypt's seat of Sunni Muslim learning, said the disposal of the body at sea was an affront to religious and human values.
Muslims set great store by interment in permanent graves on land and accept burial at sea only in cases where the body cannot be preserved intact aboard ship until it reaches shore.
A prominent Egyptian Islamist lawyer said bin Laden should have been buried in his native Saudi Arabia.
"Isn't it enough that they killed him and displayed their joy to the world?" Montasser al-Zayat told Al Jazeera. "The Kingdom of Saudi Arabia has a moral obligation to demand that it bury Osama on its land."
John Brennan, the White House counterterrorism chief, said Obama had monitored the raid from the White House and expressed relief that US forces had finally caught bin Laden without losing any more American lives.
He said US officials were weighing whether to release photographs of bin Laden's body amid calls from US legislators to prove the al-Qaeda leader is dead.
"We are going to do everything we can to make sure that nobody has any basis to try to deny that we got Osama bin Laden," Brennan told reporters on Monday.
"And so, therefore, the releasing of information, and whether that includes photographs - this is something to be determined."
According to Al Jazeera's Rosiland Jordan in Washington, the operation had been in the making for the last nine or 10 months.
"The fact that it happened inside Pakistan, there have been suggestions that Pakistani intelligence may have been protecting them," she said.
Patty Culhane, another Al Jazeera correspondent, said US authorities received intelligence last September and were able to track Bin Laden down through his couriers.
They followed them to the compound, which was reported to be worth over a million dollars.
|US officials said Bin Laden was tracked down to his mansion in Pakistan through his couriers [AFP]
Brennan said it was inconceivable that bin Laden did not have some support in Pakistan.
He said the White House was talking with the Pakistani government and pledged to pursue all leads to find out what type of support system or benefactors bin Laden might have had.
In his announcement, Obama said: "The death of Bin Laden marks the most significant achievement to date against al-Qaeda."
He said the "United States is not and will never be at war against Islam. Bin Laden was not a Muslim leader, in fact, he slaughtered many Muslims".
Just hours after the announcement, a senior al-Qaeda ideologue promised revenge.
The commentator, going by the online name Assad al-Jihad2, posted on websites a long eulogy for Bin Laden and promised to "avenge the killing of the Sheik of Islam".
The Pakistani Taliban also threatened attacks against government leaders, including Asif Ali Zardari, the Pakistani president, the Pakistan army and the US.
Elsewhere, the announcement of Bin Laden's death was met with varied responses.
Ban Ki-moon, the secretary-general of the UN, called the death a "watershed moment". "This is a day to remember the victims of terrorism here in the United States and everywhere in the world," he said at UN headquarters.
Earlier, George W Bush, Obama's predecessor, called the operation a "momentous achievement".
"The fight against terror goes on, but tonight America has sent an unmistakable message: No matter how long it takes, justice will be done," he said in a statement.
In Afghanistan, Qais Azimy, Al Jazeera's correspondent in Kabul, said Afghan officials described Bin Laden's killing as a "symbolic victory", since he was no longer directly connected to the group's field operations.
Mark Kimmit, a US military analyst, said Bin Laden's death "was not the end of terrorism, but an end of a chapter".
Brother of anti-Taliban resistance leader killed in an al-Qaeda bombing 'relieved' at news of Bin Laden's death
"Capturing or killing Bin Laden has more iconic value. It will have symbolic value, because it has been a number of years since Bin Laden has exercised day-to-day control over operations. We still have an al-Qaeda threat out there and that will be there for a number of years.
It is, however, a major accomplishment for Obama and his national security team.
Bush had repeatedly vowed to bring to justice the mastermind of the September 11 attacks on New York and Washington, but never did before leaving office in early 2009.
Bin Laden had been the subject of a search since he eluded US soldiers and Afghan militia forces in a large-scale assault on the Tora Bora mountains in 2001.
The trail quickly went cold after he disappeared, and many intelligence officials believed he had been hiding in Pakistan.
While in hiding, Bin Laden had taunted the West and advocated his views in videotapes spirited from his hideaway.
Besides September 11, the US has also linked Bin Laden to a string of attacks - including the 1998 bombings of American embassies in Kenya and Tanzania and the 2000 bombing of the warship USS Cole in Yemen.