The huge blaze broke out at around 5am (10pm United Kingdom time) at a religious school in Jalan Datuk Keramat, in Kuala Lumpur, Malaysia.
Kuala Lumpur Police Chief Amar Singh further said that police had found at least 24 charred bodies, 22 of them boys between 13 and 17, and two wardens.
The fire, which broke out at the three-story school, was most likely caused by either an electric short circuit or a mosquito zapper.
The fire broke out in the rooms before dawn, according to an official of the fire services and emergency on-site. "We are now investigating the cause of the fire".
The remains of the 23 victims who perished in a fire at a tahfiz school here have been successfully identified via DNA testing.
"The school did not acquire a permit to begin its operations but was in the midst of applying for one", fire department's director general said. "They're still counting the bodies, which were piled on top of each other in a corner", Singh said.
"I think it is one of the country's worst fire disaster in the past 20 years".More news: Kids Found Dead In West Sacramento Apartment; Man Arrested
Khirudin said investigations at the Darul Quran Ittifaqiyah Religious Residential School confirmed that the electricity circuit from the school building's main switch was in good condition.
The fire at the Tahfiz Darul Quran Ittifaqiyah softened out up the early hours of Thursday morning.
A number of students were also taken to the hospital, some suffering from smoke inhalation.
The fire broke out at around 5.40am in a top-floor dormitory in the three-storey building, firemen said, where most of the students were sleeping in bunk beds, with numerous windows covered by metal grills.
"The children were crying for help, but I couldn't help them as the door was already on fire", he said. The school also do not have any licence from the local religious authorities. "May their souls be blessed by Allah".
Religious schools, mostly privately run, are not supervised by the Education Ministry because they come under the purview of state religious authorities.
Deputy Prime Minister Ahmad Zahid Hamidi told reporters that it isn't the first such incident, adding that all Islamic religious schools were required to register and follow safety requirements.