Armed attackers seized a school in southern Russia near Chechnya on Wednesday, took up to 400 children and adults hostage and threatened to blow up the building if police tried to storm it, news agencies said. In an assault that bore the hallmarks of a Chechen operation, the group, numbering up to 17 heavily-armed men and women, stormed into the secondary school in Beslan in North Ossetia province during a ceremony to mark the first day of the new school year. Itar-Tass news agency said the attackers were demanding the release of Chechen fighters seized in neighboring Ingushetia in June during a huge rebel raid on the region. At least three civilians were killed and 11 injured in the initial phase of the attack, Tass quoted the local interior ministry as saying. The agency said nearly 50 children managed to escape. "One body is lying near the entrance to the school. Two others are on the road near a fence. The attackers are not allowing anyone to collect the bodies. They open fire when anyone tries to approach them," Tass quoted the ministry official as saying after the school attack. Reports of the exact number of hostages held varied between 200 and 400 and the number of children between 120 and 200. The school normally has about 900 schoolchildren and 60 teachers. "There could be up to 400 children and teachers held hostage," Irina Terkina, a spokeswoman for Putin's envoy in southern Russia, said by telephone. Several children had managed to escape as the drama began to unfold. "There is information that several kids managed to escape. They are now being questioned by police," Tass quoted a police source as saying. "A police patrol at the school was the first to engage in fighting with the fighters...One of the attackers was killed," the source added. **PHOTO CAPTION*** A television grab shows soldiers at the scene of hostage-taking at a school in the town of Beslan in the province of North Ossetia near Chechnya, September 1, 2004. (REUTERS)