MOSCOW (Reuters/AFP) - A gunman shot and killed a police officer and took more than 20 teenage students hostage at a high school on the outskirts of Moscow on Monday, Russian news website Lifenews reported.

A police spokesman said a man entered the school with a rifle and shot a security guard. She said she had no further details and could not confirm any deaths.

An eyewitness told Rossiya-24 television news that a police helicopter hovered overhead.

The man was the father of one of the children of Moscow school number 263, an Interior Ministry spokesman told the Interfax news agency. Initial reports said the man opened fire on police officers who rushed to the scene, killing one.