A gunman who had taken 20 students hostage in a Moscow public school was detained and all hostages were rescued, the Interior Ministry said Monday. The gunman, believed to be a senior student of the Moscow secondary school 263, killed a policeman and a teacher, and injured another police officer, the Russia 24 TV reported. The police evacuated other students and teachers of the school with no one hurt, Itar-Tass news agency quoted the Interior Ministry as saying.