Bomb and mortar attacks killed at least 20 people in and around Baghdad today in violence that showed no sign of easing despite a security crackdown against al Qaeda in the capital.
US forces were searching for two of its soldiers who went missing after an attack yesterday in which one American soldier was killed in the Sunni insurgent stronghold of Yusufiya in the "Triangle of Death" south of Baghdad.
Today's violence followed a vow by al Qaeda's new leader in Iraq to avenge the death of his predecessor Abu Musab al-Zarqawi, who was killed in a US air strike last week.
In the deadliest attack today, police said a car bomb targeting an Iraqi army checkpoint killed seven people and wounded 15 in the town of Mahmudiya, 20 miles south of the capital.
In Baghdad, where the government has launched a security crackdown with 50,000 Iraqi forces backed by 7,000 US troops to pile pressure on al Qaeda, a bomb killed six people and wounded 11 in a crowded market.
A car bomb targeting Iraqi army and police killed four people, including one soldier, and wounded 11.
Earlier, mortar rounds killed two people and wounded 14 in another market in the Shi'ite district of Kadhimiya.
Attacks on crowded markets are a common tactic used by al Qaeda as part of what US officials say is a campaign to ignite a sectarian civil war between majority Shi'ites and Sunni Arabs.
Al Qaeda's new leader, identified as Abu Ayyub al-Masri, is likely to continue the tactics of Zarqawi, a Sunni Arab militant who had concentrated mass attacks against Shi'ites.