Iraqi authorities say two car bombs have killed 13 people in eastern Baghdad.
They say Saturday's blasts also wounded 40 people in a predominantly Shi'ite area of the capital. In another Shi'ite neighborhood, gunmen dressed in Iraqi commando uniforms abducted eight people.
Iraqi officials say attacks in Shi'ite parts of Baghdad increased after Prime Minister Nouri al-Maliki vowed to crackdown on all militants. He discussed that plan by telephone with President Bush Saturday.
In another development, the U.S. military says airstrikes killed 14 militants Saturday outside Baquba.
And an explosion shook Baghdad when a rocket hit the heavily fortified Green Zone. U.S. officials say two people were slightly wounded.
Also Saturday, the U.S. military released more details about an attack on a post in Karbala last week in which four U.S. soldiers were captured, then killed. Officials say attackers wore American-style combat uniforms, carried American-style weapons and spoke English to pass Iraqi-guarded checkpoints.
Some information for this report was provided by AFP, AP and Reuters.