A rocket fell on Thursday night in the Fadhlan area of the Dujail district in Iraq's northern Salahuddin province, police sources said. The area is close to the Balad air base which houses US troops.The source of the rocket is unknown, the sources said. It caused no casualties. Dujail is 50 km (30 miles) north of Baghdad. Balad base is about 80 kilometers (50 miles) north of Baghdad.