Seven teenage suspects were arrested in relation to the fire at a religious school that killed 23 people, mostly students, Malaysian police said Saturday.

Police arrested the seven suspects, aged between 11 and 18, after obtaining surveillance videos from the neighborhood, Kuala Lumpur police chief Amar Singh Ishar Singh told a press conference.

"Factor of mischief were found in the investigation," Amar Singh said, "police successfully identified several individuals in the videos, and a total of seven were arrested."

The suspects are believed to have quarrels with the residents at the religious school and might have started the fire in retribution, Amar Singh said, declining to provide more details on how it was committed.

All seven suspects were not attending schools, six tested positive to drugs while two have criminal records, he added.

A total of 21 students aged 6 to 17 and two teachers were killed in the early morning fire on Thursday near downtown Kuala Lumpur. Investigation by fire department showed that the fire was not started by short circuit as suspected earlier.

The fire shocked Malaysia, triggering calls to strengthen fire safety measures at religious schools across the country.

source: Alarabiya