CAIRO - STREETS surrounding a police station in the Greater Cairo province of Giza were back to normal Tuseday, after the police managed to calm down protests by relatives of inmates held inside the station, where a huge fire erupted late on Monday. "Things are back to normal after the protesters were allowed to get into the el-Warraq Police Station and meet their relative prisoners, who were all safe after the blaze," a security official said. He added that some protesters were detained for hurling stones and empty bottles on policemen, setting tyres ablaze, destroying cars parking nearby and blocking streets leading to the station. A huge blaze erupted inside a prison cell of the el-Warraq Police Station late on Monday, after a prisoner set a blanket alight choking four inmates and causing some injuries to others. "A police officer was leading an inspection of the prison, when he had an argument with the prisoner leading the latter to behave this terrible way," the official said. Prosecutors started an investigation into the incident after reviewing the police station and the area outside. They also questioned the inmates and the detained protesters, whose number was not declared. Human rights groups and activists appealed to President Hosni Mubarak to dismiss Interior Minister Habib el-Adly after a New Year Eve bombing outside an Alexandria church killed 23 and injured dozens, sparking portests nationwide. They also called on el-Adly to step down for failing to protect the Copts.