Also in Baghdad, a senior government official was killed in a roadside bombing in the north of the city.
Dhia Jodi Jaber, director general at the Ministry of Labor and Social Affairs, was hit by a roadside bomb as he left his home, the ministry's spokesman Abdullah al-Lami said.
Insurgents frequently target governmental officials and institutions in a bid to disrupt the government's work.
Separately, an Iraqi court adjourned until May 20 the trial of Tariq Aziz, one of Saddam Hussein's best-known lieutenants, and seven other defendants over charges of allegedly ordering the execution of dozens of merchants for profiteering half an hour after it started.
The judge postponed the trial, saying co-defendant Ali Hassan al-Majid, Saddam Hussein's cousin who is known as "Chemical Ali," was too ill to attend.
Associated Press writers Hamid Ahmed and Sinan Salaheddin contributed to this report.