Seven young suspects have been arrested in connection with a fire at a school in Malaysia which left 21 students and two teachers dead.
Those arrested are all aged between 11 and 18, police said on Saturday.
The fire - the deadliest to strike the country in two decades - broke out early on Thursday at the Tahfiz Darul Quran Ittifaqiyah, in Kuala Lumpur.
The victims are thought to have been trapped in a dormitory, their escape blocked by metal bars on the windows.
According to police, the fire started in the sleeping quarters at about 05:40 local time on Thursday (21:40 GMT Wednesday).
Kuala Lumpur police chief Amar Singh told a press conference on Saturday that two gas cylinders had been brought up from the kitchen.
Mr Singh said it was thought there had been "teasing" between the school boys and the suspects, who are all male, before the fire was started.
He added they could face murder charges, but he told reporters the "intention was to burn, but it could be because of their age or because of their maturity levels, perhaps they may not have known that it would cause deaths".
The suspects have been remanded in custody for another seven days.
Mr Singh added: "I can assure you now that the case is solved with the arrest of the seven of them."