Children rescued

HOSPITALET DE LLOBREGAT, Spain -- A teenager with a knife took his sister and 19 other children hostage at his former school and held them for hours Monday until a plainclothes officer overpowered him while delivering a pizza, officials said.\nNone of the students was hurt in the 3 1/2-hour ordeal at the Casal de l'Angel school in this gritty, industrial town just south of Barcelona. All the hostages were 11 or 12 years old.\nThe Interior Ministry said the attacker had a knife and that his motive appeared to be money, but it could not confirm a report that he had demanded $1 million.\nThe attacker was a former pupil of the school, said Interior Minister Angel Acebes, speaking in the central city of Guadalajara. The Education Ministry said he was 16 or 17.\nThe Interior Ministry, disputing initial accounts, said there were 20 hostages altogether and that 16 were released about two hours into the ordeal. Four remained until the end.\nIt was not immediately known if the boy's sister was among the 16 hostages he had freed.\nWhile the youth held the last four, police asked if he was hungry, and he asked for pizza, the Interior Ministry said. A plainclothes policeman came back with a pizza and overpowered the youth when he opened the door to the classroom where he was holding the students, a ministry official said.\nAs a car left the schoolyard, apparently taking the assailant to a police station, a crowd swarmed around it and many people screamed insults.\nOne unidentified boy who was evacuated from the school before hostages were released said teachers rushed to his and other classrooms and took students out of the building through the cafeteria.\n"They told us some man had slipped into the school," the boy told Spanish national radio. "I was scared."\nA teacher who identified herself only as Nuria said the hostage-taker rang the doorbell at the school as if he were a parent there to pick up a student.