SAO PAULO (AP) — Inmates from rival gangs battled at a prison in Goias state Monday, leaving nine dead and 14 injured, authorities told the Brazilian news site G1. Officials said the violence at the Colonia Agroindustrial prison in the Aparecida de Goiania Complex apparently erupted when inmates from one cellblock invaded three others where prisoners from rival gangs are housed. The attackers set mattresses on fire when they entered the neighboring corridors and burned the bodies of those who were killed, authorities said.