YANGON, Myanmar — A fire engulfed a mosque housing Muslim schoolchildren in Myanmar's largest city on Tuesday, killing at least 13. Police, anxious over sectarian violence that has shaken the nation, blamed an electrical short circuit for the blaze and said they were investigating mosque authorities for possible negligence.
Security forces and three trucks of riot police blocked off roads around the scarred building in Yangon. Around 200 people, many of them Muslim, gathered uneasily nearby as some expressed suspicion that the fire had been set intentionally.
Myanmar has been on edge after sectarian unrest between Buddhists and Muslims erupted in the central city of Meikhtila in March, killing dozens of people and displacing more than 12,000. The violence, which has largely targeted Muslims, has since spread to several other towns where extremist Buddhist mobs have torched or ransacked mosques and Muslim-owned property.
Police officer Thet Lwin said about 75 children lived in the compound in eastern Yangon — which encompasses a mosque, a school and a dormitory — and most were able to escape by running out of a door rescue workers knocked open. Security bars blocked most of the building's windows, which were stained by black smoke in the late morning, hours after firefighters put out the flames.
Mosque member Soe Myint said most of the children, who had been sent to the religious boarding school by their parents, were sleeping on the ground floor when the blaze began and were able to flee.
But 16 were sleeping in a small loft and were trapped when the stairs to it caught fire. Three boys jumped to safety and the rest died, he said.
Soe Myint, who said he helped carry the dead out of the mosque, said he did not believe the fire was caused by a short circuit and urged authorities to launch a thorough investigation.
"The whole mosque smelled of diesel," he said. "We don't use diesel at the school."
But Thet Lwin, the policeman, said the fire was caused by an electrical short circuit "and not due to any criminal activity."
Every time he mentioned the word "electrical short," though, angry Muslims shouted and began banging on vehicles with their fists.
He also appealed to journalists for help. "We need the media's support in Yangon. Please don't report that there is conflict in Yangon. We're here to stop conflict," he said.
Yangon Police Chief Win Naing said authorities were investigating the head of the mosque and a teacher, but no arrests had been made. "As the two people in charge, they are responsible for this and we have to take action against them," he said.
Win Naing said the fire started in a voltage regulator under the stairs that led to the sleeping loft and that firefighters had to break two locks on the door of the mosque to rescue the survivors. He ruled out arson, saying that three police were guarding the mosque and saw no one approach the building before the fire started.
Zaw Min Htun, a member of a local Muslim youth organization, said he raced to the mosque after hearing it was on fire. He said he entered the charred building and also smelled fuel.
"Muslims are very angry," he said, calling on authorities to investigate. "The children are innocent. ... Someone burned the mosque."
Hla Myint, whose 15-year-old nephew died in the blaze, waited in a crowd outside Yangon General Hospital, where the dead were taken. Two trucks of riot police were parked nearby.
"We sent him to school only yesterday and today he is dead," she said. "We are so sad we can't express it."
Later Tuesday, several thousand mourners gathered at a cemetery on the outskirts of Yangon for a group burial. The charred bodies of the children were wrapped in white cloth before being lowered into the ground as women wept nearby.
The recent upsurge in sectarian unrest in Myanmar has cast a shadow over President Thein Sein's administration as it struggles to make democratic changes after a half century of military rule. His government has warned that the violence could threaten the reform process.
Hundreds of people were killed last year and more than 100,000 made homeless in violence in western Myanmar between ethnic Rakhine Buddhists and Rohingya Muslims. On March 20, unrest hit the central town of Meikhtila for several days and then spread to several villages farther south, near the capital, Naypyitaw.
The violence has spooked people in Yangon, where late last month false rumors swirled of mosque burnings and authorities told some shops to close as a precautionary measure. Yangon is about 550 kilometers (340 miles) south of Meikhtila.
Associated Press photographer Gemunu Amarasinghe contributed to this report.