Thirteen people died in a fire at a Muslim religious school in central Yangon early on Tuesday, officials said.

The fire, which was blamed on an electrical short-circuit, started at 2:30 a.m. (1930 GMT Monday), a source at the Information Ministry who requested anonymity said.

“All the victims were male,” he said.

Authorities ruled out foul play, but the incident was expected to raise tensions between Buddhist and Muslim communities in Yangon, the former capital and largest city.

Sectarian violence claimed 43 dead and 86 injured in central Myanmar last month after an argument in a Muslim’s gold shop in Mandalay turned into a riot that spread to other townships, forcing authorities to a state of emergency.

At least 9,000 people were left homeless.

Last year, clashes between Buddhists and Muslim-Rohingyas in the Rakhine state left 167 dead and up to 125,000 homeless.