Iraqi security officials say insurgents have carried out a series of attacks across the capital, Baghdad, despite a major security crackdown.
Police say at least 35 people are dead in and around Baghdad and many others are wounded.
In the deadliest attacks, two car bombs in the city have killed at least 17 people. Earlier attacks in two crowded markets killed at least six.
The violence comes despite the deployment of tens of thousands of Iraqi and U.S. troops in Baghdad. They are part of a large-scale security crackdown that Iraqi Prime Minister Nouri al-Maliki ordered on Wednesday.
On Friday, a group linked to al-Qaida in Iraq ,The Mujahideen Shura Council said the insurgency will not weaken despite the death last week of insurgent leader Abu Musab al-Zarqawi.
Meanwhile, the U.S. military in Iraq says the search continues for two American soldiers. They went missing Friday after their team came under attack at a checkpoint southwest of Baghdad in Yusufiyah.
U.S. Major-General William Caldwell said on Saturday that American and Iraqi troops are searching for the missing soldiers. He said the U.S. will not give up until the men are found.
The military says one U.S. soldier died in the attack late Friday.