The bodies of 23 people killed in a fire at an Islamic boarding school in Malaysia are expected to be released to their families on Friday following the completion of DNA analysis to identify remains that had been badly burnt, local media reported.

Families of the victims already were waiting at a mortuary on Friday morning, the Star Online said, a day after a fire broke out in the sleeping quarters of a tahfiz school in the country’s capital, Kuala Lumpur.

Investigations into the cause of the fire were ongoing, but two gas canisters found at the school had raised suspicions, the Malay Mail reported.

One victim was as young as seven years old, media reports said. Kuala Lumpur police chief Amar Singh had said Thursday the other victims included 21 boys aged between 13 and 17 years and two teachers.

Fourteen students and four teachers escaped or were rescued from the fire.

Malaysia has 519 registered tahfiz schools, where children are sent to memorise the Koran – but many more are believed to be unregistered.