U.S. jet fighters bombed the turbulent city of Fallujah (search) on Wednesday, killing four people and injuring four others, hospital officials said.

Several houses were damaged in the blasts, including one that was completely burnt, said emergency worker Ahmed Maher.

The shelling occurred at 5 p.m. Wednesday, said Thaer Ahmed of Fallujah hospital.

The U.S. military had no immediate comment, but U.S. forces have persistently fought with militants holed up in the city, a well known Sunni (search) stronghold, for months.

Many of the insurgents believed responsible for the spate of kidnappings, bombings and shooting attacks at coalition forces, Iraqi forces and civilians, are based in the volatile city, 40 miles west of Baghdad (search).