U.S. helicopters blasted rooftops in a Shiite neighborhood before dawn Friday as American troops battled gunmen on the ground, killing at least eight, the military said. Shiites claimed some civilians died and radicals castigated Iraq's government as being too weak to rein in the Americans, according to The Associated Press. The criticism put new pressure on prime minister, Nouri al-Maliki, who already was under fire from U.S. critics over his government's failure to achieve national unity, reported AP. Elsewhere, an explosion killed one American soldier and wounded four in Salahuddin province, a mostly Sunni Arab area north of the capital. The blast came hours after suspected al-Qaida in Iraq fighters attacked police stations in Samarra, a city in the province about 95 kilometers (60 miles) north of Baghdad, reported AP. A policeman, a woman and an 11-year-old girl were reported killed. The U.S. military said the battle in Baghdad erupted when a U.S. Army patrol came under fire shortly after midnight from gunmen on rooftops in Shula, a rundown Shiite neighborhood that is a stronghold of the Mahdi Army militia of anti-U.S. cleric Muqtada al-Sadr, reported AP.