Dec. 21 (Bloomberg) -- Insurgents fired explosives into a dining tent at a U.S. Army base in Iraq's northern city of Mosul today, killing more than 20 people, including at least 14 U.S. soldiers and seven civilians doing work for the Pentagon contractor Halliburton Co.

``The carnage was extensive,'' said Army Captain Phil Ludvigson, a spokesman in Mosul, who cited the American death toll in an interview. ``It takes some time to put together the identifications, the remains, and to get an accurate count.''

Brigadier General Carter Ham said in a Pentagon video from Mosul that the dead included Iraqi soldiers and that at least 60 people were wounded. Ham commands Task Force Olympia, a roughly 8,000-soldier force in the city, Iraq's third largest.

The attack pointed up the widespread violence aimed at U.S. forces and Iraqis as the country readies for its first democratic vote since Saddam Hussein's dictatorship was toppled last year. Three election workers were shot dead on a Baghdad street Dec. 19, and at least 63 other Iraqis died in bombings elsewhere the same day.

``The terrorists and Saddam loyalists are desperately seeking to derail the transition to democracy and freedom in Iraq,'' White House spokesman Scott McClellan said. ``The enemies of freedom understand the stakes involved.''

Lieutenant Colonel Steven Boylan, a military spokesman in Baghdad, told the Associated Press that 19 U.S. soldiers were killed. The toll, if confirmed, would be the deadliest single attack on American forces since the Iraq war began, the news agency said.

Annan Warns

United Nations Secretary-General Kofi Annan, whose organization is helping prepare for Iraqi elections next month, warned of the threat posed by insurgent attacks.

``Violence, if it continues, will have an impact on elections,'' Annan said at a news conference today in New York.

The attackers in Mosul fired rockets just as hundreds of soldiers sat down to eat, according to a Richmond Times-Dispatch reporter on the scene. The newspaper posted a photograph on its Web site taken inside the tent showing wounded soldiers being treated. In another picture, the roof of the tent was in shreds and sunlight streaked the smoke-filled air.

The force of the blasts knocked soldiers from their seats, and a fireball reached the top of the tent while shrapnel hit diners, according to the Times-Dispatch report. Soldiers overturned tables to use as stretchers, carting off the wounded.

Richmond Unit

Among the dead in Mosul were two American soldiers from a Richmond, Virginia-based engineering battalion, according to the Times-Dispatch.

``It's a sad day in Mosul,'' Ham said. Those surviving will ``do what they can do best to honor those who were fallen today, and that is to see this very important mission through to a successful completion.''

Task Force Olympia is made up largely of soldiers from Fort Lewis, Washington, with about 5,000 of the 8,000 soldiers coming from the Pacific Northwest base.

The violent Muslim group Ansar al-Sunnah said in an Internet posting that it was responsible for the attack, the Associated Press reported. Ansar al-Sunnah, a Sunni group that wants to turn Iraq into an Islamic state, in August took responsibility for the beheading 12 Nepalese hostages, AP said.

Peter Khalil, former director of national security for the Coalition Provisional Authority in Baghdad and a visiting fellow at the Brookings Institution in Washington, said the attack today was likely carried out by followers of Abu Musab al-Zarqawi, the Jordanian whom the U.S. government describes as the top terrorist leader in Iraq and an ally of al-Qaeda.

Fallujah Focus

Insurgents took advantage of the U.S. focus on a military operation in Fallujah, west of Baghdad, last month to launch an earlier Mosul attack. U.S. and Iraqi commanders were forced to deploy troops to the northern city on Nov. 11 after insurgents seized most of Mosul's police stations.

``The leadership of Musab al-Zarqawi and fighters from Fallujah escaped and made their way north to Mosul,'' Khalil, a former analyst for Australia's defense agency, said in an interview. ``They chose Mosul because it's a multiethnic, multireligious city that's been relatively stable in the past'' and their goal is to foment ethnic strife, he said.

Bush, in a news conference yesterday, said Iraq's planned Jan. 30 elections would take place regardless of how much violence occurs beforehand.

`No Road Map'

Houston-based Halliburton issued a statement saying it was ``deeply saddened'' by the deaths of four employees of subsidiary Kellogg Brown & Root and three subcontractors.

``There is no road map for coping with events like this and we are doing everything we can to support our KBR personnel in Mosul,'' the e-mailed statement said. The deaths today raised to 62 the toll of Halliburton workers and subcontractors killed in Iraq and neighboring Kuwait, a staging area for U.S. forces.

About 250 miles south of Mosul, in the Iraqi capital Baghdad, British Prime Minister Tony Blair made a surprise visit and met with Interim Prime Minister Ayad Allawi. Blair, the staunchest ally of the U.S. involvement in Iraq, said holding elections Jan. 30 will help stabilize the country.

Blair mingled among about 2,000 troops at a base that wasn't identified for security reasons and said he was sorry for taking them away from their families at Christmas to fend off insurgents, ``but, by God, it's a job worth doing.''

Britain sent 45,000 soldiers for the invasion of Iraq in March 2003. About 8,200 U.K. soldiers remain in the country.

To contact the reporter on this story: Demian McLean in Washington at dmclean8@bloomberg.net.

Last Updated: December 21, 2004 17:58 EST