Ryan Crocker, a fluent Arabic speaker with extensive experience in the Middle East, this week became the third US ambassador to Iraq in as many years and presented his credentials to President Jalal Talabani on Saturday.

Capping a week in which hundreds of Iraqis were slaughtered in attacks, the bloodshed continued with another 14 people killed in three car bombs and a roadside bombing targeting Shia areas, security officials said.

The deadliest car bombing killed five and wounded 15 wounded when it exploded outside the Al-Sadr hospital in Baghdad's Shia enclave of Sadr City, named after the ayatollah father of radical anti-US cleric Moqtada Sadr.