KAMPALA, Uganda >> Suspected rebels attacked a school in a remote area of Uganda near the Congo border, killing at least 41 people in a nighttime raid before fleeing across the porous frontier, authorities said. Thirty-eight students in their dormitories were among the victims.

Some students were burned beyond recognition, and others were shot or hacked to death after militants armed with guns and machetes attacked the school in the frontier district of Kasese, a local mayor told The Associated Press.

In addition to the 38 students, one guard and two residents of the local community in Mpondwe-Lhubiriha town were killed in the attack, said Mayor Selevest Mapoze. A Ugandan military statement said the rebels abducted six students, taken as porters of food looted from the school’s store.

The school, co-ed and privately owned, is located about two kilometers (just over a mile) from the Congo border.

Authorities are blaming the massacre at Lhubiriha Secondary School on the Allied Democratic Forces, or ADF, a shadowy extremist group which has been launching attacks for years from bases in volatile eastern Congo. Villagers in the Congolese provinces of Ituri and North Kivu have been the victims of the group’s alleged attacks in recent years.

But attacks on the Ugandan side of the border are rare, thanks in part to the presence of an alpine brigade of Ugandan troops in the region.

The attack has sent shockwaves in this normally peaceful East African country whose long-time leader cites security as a strength of his government. It is also a blow to the country’s armed forces, who since 2021 have deployed in parts of eastern Congo under a mission specifically to hunt down the militants accused of attacking a school.

Speaking to reporters near the scene of the attack, the commander of Ugandan troops in Congo told reporters that the rebels spent two nights in Kasese before carrying out their attack. He gave no further details.

ADF rebels, when under pressure, “divert” their pursuers’ attention by splitting into small groups that then launch violent attacks in other places, said Maj. Gen. Dick Olum, suggesting that the latest attack was an attempt by the rebels to ease battlefront pressure.

“A typical ADF signature,” he said, “because this is pressure. They are under huge pressure, and that’s what they have to do to show the world that they are still there, and to show the world that they can still do havoc.”

The school raid, which happened around 11:30 p.m., involved about five attackers, according to the Ugandan military. Soldiers from a nearby brigade who responded to the attack found the school on fire, “with dead bodies of students lying in the compound,” military spokesman Brig. Felix Kulayigye said in a statement.

Winnie Kiiza, an influential political leader and a former lawmaker from the region, condemned the “cowardly attack” on Twitter. She said “attacks on schools are unacceptable and are a grave violation of children’s rights,” adding that schools should always be “a safe place for every student.”

The ADF has been accused of launching many attacks in recent years targeting civilians in remote parts of eastern Congo. It rarely claims responsibility for attacks.

The ADF has long opposed the rule of Ugandan President Yoweri Museveni, a U.S. security ally who has held power in this East African country since 1986.

The group was established in the early 1990s by some Ugandan Muslims, who said they had been sidelined by Museveni’s policies. At the time, the rebels staged deadly attacks in Ugandan villages as well as in the capital, including a 1998 attack in which 80 students were massacred in a town not far from the scene of the latest attack.

A Ugandan military assault later forced the ADF into eastern Congo, where many rebel groups are able to operate because the central government has limited control there. The group has since established ties with the Islamic State group.

In March, at least 19 people were killed in Congo by suspected ADF extremists.

Ugandan authorities for years have vowed to track down ADF militants even outside Ugandan territory. In 2021, Uganda launched joint air and artillery strikes in Congo against the group.