At least 24 students and teachers have died in a fire at a religious school in Malaysia's capital, Kuala Lumpur.
The fire at the Tahfiz Darul Quran Ittifaqiyah broke out in the early hours of Thursday morning, reports BBC.
The victims are thought to been trapped in their dormitory as the windows were barred with metal grills.
"It is one of the country's worst fire disasters in the past 20 years," Khirudin Drahman, director of the fire and rescue department, told a global news agency.
Initial counts put the death toll at 25, but police later revised that down by one.
They said the dead were 22 students - all boys between the age of 13 and 17 - and two staff members.
The blaze was reported at around 05:40 local time on Thursday morning (21:40 GMT Wednesday). According to the police it began in the sleeping quarters.
In Islamic tahfiz schools - where children study the Koran - students often live at the school.
Images and videos circulating online showed the entire upper room of the school ablaze.
"The building was surrounded by metal grills that could not be opened from the inside. The students, after realising the fire and heavy smoke, tried to escape through the window," Fire and Rescue Department operations deputy director Soiman Jahid told reporters outside the school.
"Because of the grills though, they could not escape."
Mr Jahid said police were still investigating what caused the fire but that it likely was caused by short circuit or a lit mosquito repellent coil.
A neighbour living next door to the school told the Reuters news agency they heard screams and saw the flames.
"The children were crying for help, but I couldn't help them as the door was already on fire," he said.
Kuala Lumpur Police chief Amar Singh said the bodies were "totally burned".
"Unfortunately there was only one entrance, so they could not escape. All the bodies were found lumped on one another."
Officials said fire engines were at the site within minutes, and the blaze was put out within an hour.
A number of students were also taken to hospital, some suffering from smoke inhalation.
Prime Minister Najib Razak tweeted his sympathies to those affected while a government minister said the incident should be quickly investigated "so that we will be able to prevent future disasters".
Malaysian authorities have raised concerns about safety measures at unregulated private religious schools.
Local media report there have been more than 200 fires at such schools since 2015.