A suicide bomber killed at least three Iraqis and an American soldier in Baghdad Tuesday.
The blast wounded 50 others. Also Tuesday, insurgents killed 10 police officers across the capital.
Despite the violence, Iraqi political leaders met for a second round of talks on the Iraqi constitution. A draft constitution is due Monday, but issues such as federalism, women's rights, the role of Islam and the country's official language still need to be agreed upon.
Iraqi officials say they are confident the deadline can be met. And U.S. Defense Secretary Donald Rumsfeld said the constitution could turn out to be a powerful weapon against insurgents.
Mr. Rumsfeld, in Washington, also said weapons are entering Iraq from Iran, but that is unclear if the Iranian government is involved in the weapons smuggling. He called it "unhelpful" that Iranians are allowing weapons to cross the border.