Civilian deaths in US military strike bring worries of Sunni backlash

The deaths of nine civilians, including a child, in a U.S. airstrike south of Baghdad have raised fresh concerns about the military's ability to distinguish friend from foe in a campaign to uproot insurgents from Sunni areas on the capital's doorstep.

Witnesses and Iraqi police said helicopters strafed a house Saturday after confusing U.S.-allied Sunni fighters for extremists in the deadliest case of mistaken identity since November. The U.S. military on Monday confirmed the civilian deaths, but gave few other details of the Army gunship attack.

The bloodshed also points to the wider complications for U.S.-led offensives against insurgents in populated …