One hundred or more people were killed when Russian troops stormed a school Friday in a chaotic battle to free children, parents and teachers who had been held hostage for 53 hours by Chechen separatists.

Amid confusion and carnage, authorities said they had been forced into an unplanned operation by hostage-takers who opened fire on fleeing children. Some children were still being held hours after the raid, officials told Interfax news agency.

Machinegun fire and explosions boomed out and helicopters clattered overhead as naked children ran for safety, screaming.