Other developments in Iraq

Roadside bombs in separate guerrilla attacks killed two U.S. soldiers and two Iraqi children on Sunday, including one explosion that went off in Baghdad.

Hundreds of weeping and wailing mourners buried victims of a Saturday attack in the holy Shiite city of Karbala -- the biggest since the Dec. 13 capture of Saddam Hussein -- as the death toll rose to 19.

Officials said they arrested five Iraqi suspects in the Karbala attacks, said Lt. Rafal Smilkowski of the Polish regiment that commands a force in south-central Iraq.

Despite the latest attacks, U.S. military officials say the number of assaults has dropped from about 50 a day in mid-September to an average of 14 or 15 a day, spiking to 18 on Christmas Day.