At least four police officers were injured Saturday in separate attacks across Iraq while a blanket curfew was imposed in the northern city of Samraa, 125 kilometers north of Baghdad, DPA quoted Iraqi officials and media as saying. In Kirkuk, two police officers were injured when an explosives- laden vehicle detonated targeting their patrol, Voices of Iraq (VOI) news agency reported. The injured have been taken to the nearest hospitals, sources told VOI. Nearby shops were damaged by the explosion. In Basra, some 550 kilometers south of Baghdad, two police officers were wounded when militants opened fire on an Iraqi patrol, sources told Deutsche Presse-Agentur DPA. Militants escaped after opening fire on the patrol in the al-Jumhuria district of Basra, sources said. Meanwhile, another police officer survived an explosion uninjured in Basra. In Samraa, Iraqi forces imposed a blanket curfew on people and vehicles, sources told VOI.