BAGHDAD — Two Marines were killed Sunday in Al Anbar province west of the capital, bringing the weekend U.S. death toll to at least 27, a dramatic increase in fatalities that comes as President Bush is trying to convince a wary public of his plan to escalate the military presence in Iraq.
The U.S. military also reported that at least five more U.S. soldiers and one Marine had died in separate combat incidents in Baghdad and Al Anbar on Saturday, the third-deadliest day for American forces since the March 2003 invasion of Iraq.
Another 44 Iraqis were killed or found dead in political and sectarian violence, including the bombing of a bus in a middle-class Shiite Muslim neighborhood of Baghdad that left seven dead and 15 injured.
A British soldier was killed Sunday when his vehicle struck a roadside bomb in the southern city of Basra. Four British soldiers were injured in the blast.
The deaths come as the U.S. begins to deploy thousands of additional troops into Iraq, the first of 21,500 meant to bolster forces that must confront Shiite and Sunni Arab gunmen in a complex peacekeeping and counterinsurgency mission.
The bulk of the U.S. deaths Saturday came in the crash of a Black Hawk helicopter northeast of Baghdad. Twelve soldiers were killed.
U.S. officials have not announced the cause of the crash.
A witness and an insurgent group said that hostile fire had struck the aircraft. CNN, reporting from Washington, quoted an anonymous Pentagon official saying that the crash was probably caused by insurgent fire.
In Saturday's most audacious guerrilla attack, gunmen in sport utility vehicles and uniforms stormed a provincial security building in Karbala as U.S. and Iraqi officials discussed plans to protect pilgrims during an upcoming Shiite religious festival. The gunmen made their way past checkpoints and burst into the building, guns blazing.
Five U.S. soldiers were killed and three injured in the attack.
Karbala is a Shiite stronghold that abuts the Sunni Arab heartland. U.S. and Iraqi officials would not disclose whether they suspected Shiite militants or Sunni insurgents in the attack.
"The mystery that accompanied this operation was so deep that we can't accuse any side," Aqil Khazali, the governor of Karbala province, told reporters.
The city of Karbala has fallen under the sway of radical Shiite cleric Muqtada Sadr and his Al Mahdi army. But officials loyal to Sadr's movement, which on Sunday ended a largely symbolic boycott of the Iraqi government, denied that the Al Mahdi army had staged the assault.
