MOSCOW - Four people taken hostage by a gunman in the Southern Russian city of Astrakhan have been released, local investigators said Thursday.

The hostages were released with the help of police after being taken hostage by a gunman in the city's downtown at about 14:00 Moscow time (1000 GMT), local police told Interfax news agency.

The 25-year-old gunman, who was identified as Alexander Kuptsov, had held two young girls in a classroom at the Volga-Caspian marine fishing industry college. He had claimed to be armed with weapons and explosives, the Investigative Committee of Astrakhan region said earlier.

One hostage was later released by the gunman. During a special operation, the other hostages were also set free and the gunman was detained, local police said, adding no one got hurt in the operation.

A spokesman with the local Investigative Committee told reporters that a criminal case was opened against the gunman. If found guilty, he may face six to fifteen years of imprisonment.