An insurgent bomb attack killed at least four Iraqis Tuesday in Baghdad.

Officials say the bomb was aimed at nearby police officers. Elsewhere in the capital, the U.S. military says five insurgents were killed and seven captured during a massive firefight with Iraqi troops in a Sunni Arab district.

West of Baghdad, heavy fighting erupted Monday between U.S. forces and insurgents hiding in a mosque in Ramadi. No details on casualties are available.

Iraqi leaders remain deadlocked on forming a new government as fighting raged on across the country. Parliament was due to open Monday, but that session was put off as Shi'ites, Sunni Arabs and Kurds tried to agree on who will serve as prime minister.

Some information for this report provided by AP, AFP and Reuters.