At least 13 boys have been killed after a fire ripped through their makeshift home at an Islamic school in Burma.
Officials said the blaze in Rangoon was started by an electric fault "and not due to any criminal activity".
"The fire, caused by the overheating of the transformer placed under the staircase, spread, trapping the boys sleeping in the attic. As a result, 13 twelve-year-old boys died of suffocation after inhaling smoke," a fire service officer said in a statement.
However, many Burmese Muslims voiced concerns the mosque had been targeted in a sectarian attack following violence between Buddhists and Muslims in the central city of Meikhtila in March.
"The whole country is worried now for Yangon (Rangoon), and is wondering whether this was a crime," Ye Naung Thein, secretary of Muslim organisation Myanmar Mawlwy federation, said.
The violence, which Rangoon largely avoided, has killed dozens of people and displaced more than 10,000.
A teacher who helped evacuate survivors said he had smelt petrol during the blaze, a claim repeated by several other witnesses.
"I think someone started the fire intentionally," Khin Maung Hla said.
Police officer Thet Lwin said the mosque in eastern Rangoon sheltered about 75 orphans, and most escaped unharmed by running out of a door after police knocked it open.
Firefighters extinguished the blaze and the two-storey building was charred but intact.
The fire service said it was setting up a team to investigate the blaze with the police, the electricity company and representatives of Muslim groups.
Colonel Win Naing, chief of Rangoon Division police, said a case had been opened that could lead to action for negligent homicide being taken against those responsible for the mosque.
An official at the mosque where the surviving children were now being housed said that an imam had been taken in for questioning.
Neighbours and witnesses said the doors to the dormitory may have been locked due to security concerns following the sectarian violence.
At least 5,000 people attended a funeral service for the victims on Tuesday afternoon.