(Adds details) BAGHDAD, Dec 4 (Reuters) - A suicide bomber killed six people and wounded 25 when he blew himself up outside a police station in Iraq's Diyala province on Tuesday, police said. The bomber struck in the town of Jalawla, 110 km (70 miles) north of Baghdad in the Diyala River valley. Police earlier said a suicide car bomber caused the attack, but they later said it was a militant wearing a vest packed with explosives. The attack took place near a popular market. Among those killed were two policemen. Diyala is an ethnically and religiously mixed area that has seen some of the worst fighting between U.S. forces and militants over the past several months. Violence in Iraq has dropped sharply recently, but has not ceased. According to Iraqi government figures, 538 civilians were killed last month in attacks compared with nearly 2,000 a month at the beginning of the year. (Writing by Peter Graff, Editing by Dean Yates)
