Around 40 people, mostly pupils, have been killed at a school in western Uganda by rebels linked to the Islamic State group (IS).
A further eight people remain in a critical condition after the attack on Lhubiriha secondary school in Mpondwe.
Boys staying in dormitories are among the dead. Several others, mostly girls, have been abducted, authorities say.
The Allied Democratic Forces (ADF) - based in the Democratic Republic of Congo (DRC) - have been blamed.
The attack happened at around 23:30 (20:30 GMT) on Friday at the school in the Kasese district in western Uganda.
Over 60 people are educated at the school, most of whom live there.
Some five suspected ADF rebels carried out the attack, burning the school buildings and looting the food store, the Ugandan army has said.
Some of the boys were burnt or hacked to death, Maj Gen Dick Olum from the army told the media
The ages of the victims are not known.
Some of the bodies are said to have been badly burnt and DNA tests will need to be carried out to identify them.
The attackers are said to have torched the students' mattresses and are also thought to have detonated bombs in the region.
Photos of burning buildings at the school have circulated on social media.
Members of the wider community are possibly among the dead. A number of students remain unaccounted for and the exact number of those who died is still unclear.
Many of the bodies were transferred to Bwera Hospital, national police spokesperson Fred Enanga said.
Soldiers are pursuing ADF insurgents towards the DRC's Virunga national park - Africa's oldest and largest national park which is home to rare species, including mountain gorillas.
Militias including the ADF also use the vast expanse, which borders Uganda and Rwanda, as a hideout.
"Our forces are pursuing the enemy to rescue those abducted and destroy this group," defence spokesperson Felix Kulayigye said on Twitter.
The Ugandan army has also deployed helicopters to help track the rebel group over mountainous terrain.