Eleven boys perished and another 20 suffered severe burns in a fire that gutted their dormitories in Uganda while they slept.
The schools headmaster said he suspected some students who had been expelled recently were behind the "heinous act".
The fire ripped through the St Bernard Secondary School in Rakai on Sunday night.
Area police chief Ben Nuwamanya said that 11 students have been confirmed dead.
"About 20 students have been admitted with severe burns and are in critical condition but doctors say some will stabilise," he added.
Nuwamanya said the cause of the fire had yet to be established, and that three people, including a guard at the school, had been arrested for questioning.
The Rakai district lies about 280 kilometres south of the capital Kampala, near the border with Tanzania.
