At least 20 people, some of them U.S. soldiers, were killed and more than 60 wounded in a lunchtime attack Tuesday at a base near Mosul in Iraq, military officials said.
"It is indeed a very, very sad day," said Brig. Gen. Carter Ham, commander of Task Force Olympia, in a brief televised statement from Mosul.
Two military officials, discussing early reports of the attack on the condition of anonymity, said several rockets were fired at the base, and at least one rocket struck the base mess hall, causing most the casualties.
The identities of the attackers were unknown, though a radical Muslim group later claimed responsibility.
"The killed include U.S. military personnel, U.S. contractors, foreign national contractors and Iraqi army. The wounded also come from those various groups," Ham said.
One Pentagon official put the death toll at 22; another military official said it was around 20.
The attack occurred a day after President Bush acknowledged that a wave of deadly attacks has raised questions among Americans about whether Iraqis will one day be able to take over from U.S. forces.
It occurred at lunchtime in a large mess tent crowded with soldiers, according to Jeremy Redmon, a reporter for the Richmond, Va., Times-Dispatch embedded with troops in Mosul. He said the force of the explosions knocked soldiers off their feet and out of their seats.
Redmon reported that members of the Richmond-based 276th Engineer Battalion were among hundreds who had just sat down for lunch in the giant tent. He said two from the battalion were among 13 soldiers who were killed.
He said Americans were among the dead at Forward Operating Base Marez, Iraq, but two military officials could not break down the casualties between American and Iraqi.
The base, used jointly by the United States and Iraq, is also used by members of the Stryker Brigade, based at Fort Lewis, Wash., one military official said.
The killings were the latest violence in the city, which was initially peaceful after the U.S.-led invasion but become a worrisome trouble spot since U.S. and Iraqi troops invaded the insurgent stronghold of Fallujah, west of Baghdad, in November.
On Sunday, insurgents detonated two roadside bombs and a car bomb targeting U.S. forces in the volatile city of Mosul 225 miles northwest of Baghdad, in three separate attacks during a two-hour period. Other car bombs Sunday killed 67 people in the Shiite holy cites of Najaf and Karbala.
Iraq's interim prime minister, Ayad Allawi, warned Monday that insurgents are trying to foment sectarian civil war as well as derail elections scheduled for next month.