Sources: US in possession of Osama's body

Osama bin Laden, the mastermind behind the Sept. 11, 2001, attacks against the United States, is dead, and the U.S. is in possession of his body, a person familiar with the situation said late Sunday.

President Barack Obama was expected to address the nation on the developments Sunday night.

Two senior counterterrorism officials confirmed that bin Laden was killed in Pakistan last week. One said bin Laden was killed in a ground operation, not by a Predator drone. Both said the operation was based on U.S. intelligence, and both said the U.S. is in possession of bin Laden's body.

Officials long believed bin Laden, the most wanted man in the world, was hiding a mountainous region along the Pakistan-Afghanistan border.

The officials spoke on the condition of anonymity in order to speak ahead of the president's statement.

The development comes just months before the tenth anniversary of the 2001 attacks on the World Trade Center towers in New York and the Pentagon in Washington, orchestrated by bin Laden's al-Qaida organization. The attacks killed more than 3,000 people.

The attacks set off a chain of events that led the United States into wars in Afghanistan, and then Iraq, and America's entire intelligence apparatus was overhauled to counter the threat of more terror attacks at home.

Al-Qaida organization was also blamed for the 1998 bombings of two U.S. embassies in Africa that killed 231 people and the 2000 attack on the USS Cole that killed 17 American sailors in Yemen, as well as countless other plots, some successful and some foiled.