An explosion killed at least four Iraqi police recruits and wounded 23 others in Baghdad today, Iraqi police said.
The recruits were gathered at a police recruiting centre in western Baghdad when they came under attack.
There were conflicting police reports on the cause of the blast. One police source said it was a mortar round. Another said it was a roadside bomb.
Two other roadside bombs targeting police patrols in different parts of the capital today wounded four policemen and five civilians, police said.
Thousands of police and police recruits have been killed in attacks across Iraq since the 2003 US-led invasion, many of them targets of Sunni Arab insurgents.
Violence has declined following President George W. Bush's decision to send 30,000 extra troops to Iraq, a rebellion by Sunni tribal leaders against al Qaeda insurgents and a ceasefire ordered by anti-American Shia cleric Moqtada al-Sadr.