Nigerian city under curfew after coordinated bombs kill 7 January 21, 2012 -- Updated 0622 GMT (1422 HKT) Terrified residents lock themselves at home Fatalities include at least two police officers and a journalist Islamist militant group Boko Haram claims responsibility (CNN) -- Nigeria imposed a 24-hour curfew in the northern city of Kano after assailants killed at least seven people in a hail of gunfire and coordinated bombings of eight government sites. Fatalities included at least two police officers and a journalist, Nigerian police said in a statement. The number of people injured was unclear early Saturday. The attacks targeted several police stations, barracks and the building housing the assistant inspector general of police in Kano. Other sites struck included a passport office, state security headquarters and the immigration office, police said. Terrified residents barricaded themselves in their homes, said the Rev. Murtala Mati. "The government is really trying but we are afraid ... we are all scared," he said. During the attack, assailants entered a police station, freed detainees and bombed it, authorities said. They later canvassed the area in a car led by motorcycles, spraying targets with gunfire. Islamist group Boko Haram claimed responsibility for the blast in a phone call to the Daily Trust, according to journalists at the newspaper. Boko Haram has been blamed for months of widespread bloodshed, with churches and police stations among the targets.