Seven hearses numbered 1 to 7 could be seen at the grounds of the National Forensic Medicine Institute at Kuala Lumpur Hospital here.
"The sad part is, during this incident, there was only one entrance to exit through, so the students were trapped inside", Singh said.
A fire and rescue spokesperson said, "Based on our information at the moment, 25 students and teachers have died in the fire".
Officials said the bodies were piled on top of each other, indicating a stampede in an effort to flee the burning building.
The blaze was reported at around 05:40 local time on Thursday morning (21:40 GMT Wednesday). As indicated by the police it started in the resting quarters.
Images and videos circulating online showed the upper floor of the school, where students would have been sleeping, ablaze.
Soiman Jahid, deputy director of Fire and Rescue Department, said numerous victims were found dead by the windows on the third floor because they were trapped by the fix grills on the windows. Officials suspected an electrical short circuit, with Singh saying that no foul play had likely been behind the incident.More news: 'Frank from Falls Church' mows lawn at White House
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The school was said to have just been submitted to the city council for building safety approval, while - like many religious schools - it was claimed to be unlicensed with local authorities.
Such schools are unregulated by Malaysia's education ministry, falling instead under the religious department, reports Al-Jazeera. After that, I heard three explosions from inside and suddenly the voices were gone.
He said the victims who were students were all boys aged between 13 and 17. Some boys were able to open one window, witnesses said, and about 14 escaped that way. He said they found a pile of bodies in the right corner of the dorm and another pile in the left corner.
Deputy prime minister Ahmad Zahid Hamidi said at least 31 fires had been reported at such schools in Malaysia since 2011, adding that they must follow safety regulations.
The cause of the fire is not yet known but a government minister has already called for an investigation.
"We identify with the families".