World leaders welcomed Bin Laden's death but the relief was tempered by fears of retaliation and warnings of the need for renewed vigilance against worldwide attacks on US interests.
US President Barack Obama said: "This is a good day for America. Our country has kept its commitment to see that justice is done. The world is safer."
US officials said a US Navy SEALs strike team, dropped by helicopter to Bin Laden's compound under the cover of darkness, took out the Al-Qaeda leader in a firefight.
"This was a kill operation," one security official said.
An official familiar with the operation said Bin Laden was hit by a barrage of carefully aimed return fire. Other officials said Bin Laden was killed near the end of the 40-minute firefight.
The SEALs retrieved Bin Laden's body and turned the detainees over to Pakistani authorities. They did not disclose the number of people detained, but sources said there were women and children among them.
Bin Laden was killed with five others — a son, three of his associates and a woman.
The revelation that Bin Laden was living in a three-story residence in the garrison town of Abbottabad, and not as many had speculated, in the country's lawless western border regions, is a huge embarrassment to Pakistan, whose relations with Washington have frayed under the Obama administration.
A US intelligence official said there was no indication that Pakistan was aware that Bin Laden was sheltering at the compound. Reflecting the lack of trust between the United States and Pakistan, US officials said they did not tell Pakistan about the operation until it was over.
Muslim scholars said Bin Laden's burial at sea was a violation of Islamic tradition that may further provoke calls for revenge attacks against American targets.
Although there appears to be some room for debate over the burial, a wide range of senior Islamic scholars interpreted it as a humiliating disregard for the standard Muslim practice of placing the body in a grave with the head pointed toward the Kaaba. Sea burials can be allowed, they said, but only in special cases where the death occurred aboard a ship.
President Obama said the remains had been handled in accordance with Islamic custom, which requires speedy burial, and the Pentagon later said the body was placed into the waters of the northern Arabian Sea after adhering to traditional Islamic procedures — including washing the corpse — aboard the aircraft carrier USS Carl Vinson.
US officials explained the sea burial with nations refusing to accept the body and fears of a burial place on land being turned into a shrine in the future.
DNA tests on the body of Bin Laden showed a virtual 100 percent match to relatives, and a woman believed to be his wife also identified him by name, a senior US intelligence official told reporters.
The United States was now reviewing a large cache of materials seized at the compound in Pakistan, the official said. "Those materials are currently being exploited and analyzed and a task force is being set up at CIA ... given the volume of materials collected at the raid site," the official said.
An Internet outlet for official messages from Al-Qaeda has accepted its leader's killing and eulogized him as a knight who sacrificed his soul and money to fight the United States, monitoring group SITE said.
Some US law enforcement agencies were adding security measures out of what one called "an abundance of caution." In Los Angeles, police were stepping up intelligence monitoring, and New Yorkers will see extra police at their airports, bridges and the World Trade Center site itself.
The Port Authority of New York and New Jersey said it will add more police at the facilities it runs, which include the airports, the George Washington Bridge and ground zero.
The measures are not a response to any current threat and all the facilities will operate normally otherwise, the Port Authority said. "This response is not based on a current threat, but out of an abundance of caution until we have the chance to learn more," the agency said.
Eighty-four Port Authority employees died in the attack on the World Trade Center on Sept. 11, 2001.
New York Police Commissioner Ray Kelly issued a message to all police commands reminding them that while there is no information indicating a specific threat to the nation's biggest city, officers should remain alert.
In Los Angeles, a top counterterrorism commander said police will be stepping up intelligence monitoring. Assistant Commanding Officer Blake Chow, who heads the department's counterterrorism and special operations bureau, said that officers will be keeping a close ear on intelligence buzz to develop immediate response plans accordingly.
Police in Philadelphia were on heightened alert, checking on mosques and synagogues every hour, Lt. Raymond J. Evers said.
Interpol predicted a heightened risk and called for extra vigilance in case Bin Laden's supporters sought revenge for the killing.
France's President Nicolas Sarkozy welcomed the killing as a coup in the fight against terrorism, but both he and Foreign Minister Alain Juppe warned it did not spell Al-Qaeda's demise.
British Prime Minster David Cameron also said the West would have to be "particularly vigilant" in the weeks ahead.
