The chairman of the U.S. Joint Chiefs of Staff, Richard Myers, says a suicide bomber apparently caused the explosion that killed 22 people, including 13 American troops, on a U.S. military base near the northern Iraqi city of Mosul.
During a news conference at the Pentagon General Myers says a team investigating the source of the explosion has determined that a suicide bomber is apparently to blame.
"Investigators are about to conclude their look into the exact cause of the blast," he said. "At this point it looks like it was an improvised explosive device worn by an attacker. I assure you that everything possible is being done to get to the bottom of what happened and to take the appropriate steps so we can prevent potential future attacks of this nature."
It is not yet clear how a bomber was allowed to enter the base or the dining hall where hundreds of U.S. troops, Iraqi National Guardsmen and civilian contractors were eating lunch.
The militant group Army of Ansar al-Sunna claimed responsibility for the attack, calling it a "martyrdom operation."
General Myers defended efforts to protect U.S. military personnel in Iraq, saying that stopping anyone determined to commit suicide is very hard.
"We have had a suicide bomber, apparently, strap something to his body, apparently a him, and go into a dining hall," he added. "We know how difficult this is to prevent suicide, people bent on suicide and stopping them."
Despite the continuing violence, General Myers says coalition forces are determined that elections scheduled for January 30 in Iraq will be held on time.
At the same news conference, U.S. Defense Secretary Donald Rumsfeld said he expects the insurgency to continue after the elections.
"I think looking for a peaceful Iraq after the elections would be a mistake," he noted. "I think our expectations level ought to be realistic about that. These folks have a lot to lose. The extremists and the terrorists and the people who are determined to try to take back that country are determined not to lose and they are going to do everything they can to see that opportunity they have succeeds, and we have got to do everything to see that they fail."
Even with the assault on the military base near Mosul, Secretary Rumsfeld insisted that U.S.-led forces are winning the battle against the insurgents, and in the process protecting America from another terrorist attack.