U.S. officials say Osama bin Laden is dead, and CNN is reporting that authorities have his body.

UPDATE 1: In a late-night address from the White House, President Obama reported that Osama Bin Laden was tracked down by American military and C.I.A. operatives and killed on Sunday during a firefight in Pakistan. He said:

"The American people did not choose this fight. It came to our shores. And started with the senseless slaughter of our citizens. After nearly ten years of service, struggle and sacrifice, we know well the costs of war. These efforts weigh on me every time I, as commander in chief, have to sign a letter to a family that has lost a loved one or look into the eyes of a service member who's been gravely wounded. So Americans understand the costs of war. Yet as a country, we will never tolerate our security being threatened, nor stand idly by when our people have been killed. We will be relentless in defense of our citizens and our friends and allies. We will be true to the values that make us who we are. And on nights like this one, we can say to those families who have lost loved ones to al Qaeda's terror, justice has been done."

UPDATE 2: Crowds are celebrating outside the White House and at Ground Zero. The New York Times has collected reactions from several political leaders, including Bill Clinton, Nancy Pelosi, and John McCain. George W. Bush said:

"Earlier this evening, President Obama called to inform me that American forces killed Osama bin Laden, the leader of the al Qaeda network that attacked America on September 11, 2001. I congratulated him and the men and women of our military and intelligence communities who devoted their lives to this mission. They have our everlasting gratitude. 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. The fight against terror goes on, but tonight America has sent an unmistakable message: No matter how long it takes, justice will be done."

UPDATE 3: After hearing the news, fans at the Phillies-Mets Game chanted "U.S.A! U.S.A! U.S.A!"

UPDATE 4: MSNBC has more information on how intelligence officials tracked bin Laden and the fight that led to his capture. Senior officials say no U.S. personnel were killed during the mission, adding, "This operation was a surgical raid by a small team designed to minimize collateral damage. Our team was on the compound for under 40 minutes and did not encounter any local authorities."

Bin Laden fired weapons during the battle, and another official says, "He did resist the assault force, and he was killed in a firefight." Four men were killed: bin Laden, his son, and two couriers. One woman was injured and "one woman killed when used as a shield."

Officials say they're handing bin Laden's body carefully. "We are assuring it is handled in accordance with Islamic practice and tradition," says an official. "We take this very seriously. This is being handled in an appropriate manner."

There's concern that there will be retaliatory attacks from bin Laden supporters, and the State Department has issued a travel ban for Pakistan. "In the wake of this operation, there may be a heightened threat to the U.S. homeland. The U.S. is taking every possible precaution," says a government source.

UPDATE 5: A Pakistani TV station aired footage of a fire at a compound, which is believed to be a scene from the raid that killed bin Laden.

UPDATE 6: The Associated Press is reporting that bin Laden was buried at sea:

After bin Laden was killed in a raid by U.S. forces in Pakistan, senior administration officials said the body would be handled according to Islamic practice and tradition. That practice calls for the body to be buried within 24 hours, the official said. Finding a country willing to accept the remains of the world's most wanted terrorist would have been difficult, the official said. So the U.S. decided to bury him at sea.

Bin Laden Dead, President Obama Says [NYT]
Text Of President Obama's Statement To U.S. People [Reuters]
After Killing of bin Laden, Official Reaction Pours In [NYT]
Osama Bin Laden Death Prompts USA Chants At Phillies-Mets Game (VIDEO) [HuffPo]
US Tracked Couriers To An Elaborate Bin Laden Compound[MSNBC]
Official: Bin Laden Buried At Sea [AP]