Six servicemen died and twelve were injured in the explosion at a training range in the Astrakhan region, a regional police source told Itar-Tass. "The explosion happened in the disposal of old munitions. Six servicemen died instantly. Twelve were injured. Information about casualties is being updated," he said. Causes of the accident are so far unknown. "There is a theory that the explosion might have happened by neglect of safety rules," he said. "According to the preliminary information, the explosion did not spark a fire. There is no danger to local population," the source said.