Updated

The police chief in Malaysia's capital says authorities have arrested seven teenagers suspected of intentionally starting a deadly blaze an Islamic boarding school that killed 23 people.

Kuala Lumpur police chief Amar Singh says the seven arrested boys lit Thursday's fire because they had been mocked by students at the school.

Singh said in a press conference late Saturday that the boys aged 11 to 18 had also tested positive for drugs.

The blaze at a three-story "tahfiz" school, where Muslim boys study and memorize the Quran, blocked the lone exit to the dormitory, trapping students behind barred windows.