Shiite fighters launch attack on US base

Iraqi Shiite militiamen fired several mortar shells at a US base in Najaf early today and at a city hall guarded by Bulgarian troops in another Shiite city. Four US soldiers died after their Humvee overturned during a combat patrol north of Baghdad, the Army said.

The overnight shelling of the US base in Najaf followed intense attacks yesterday by militiamen loyal to radical cleric Muqtada al-Sadr, who pounded the base with mortars and fired rifles and machine guns.