Osama bin Laden, the mastermind behind the Sept. 11, 2001, terror attacks that killed thousands of Americans, was killed in an operation led by the United States, President Barack Obama announced Sunday.

“Justice has been done,” President Barack Obama said during a late-night statement at the White House. “Yet (bin Laden’s) death does not mark the end of our effort. There’s no doubt that al Qaeda will continue to pursue attacks against us. We must – and we will – remain vigilant at home and abroad.”

A small team of Americans executed the operation and took custody of bin Laden’s remains.

U.S. forces killed bin Laden just months before the 10th anniversary of the Sept. 11 attacks on the World Trade Centers and Pentagon led by bin Laden’s al-Qaida organization. Those attacks killed more than 3,000 people and led the U.S. into wars in Afghanistan and Iraq.

Al-Qaida organization has also been 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.