DAKAR, Senegal — A militia backed by Congolese forces rampaged through a hospital and killed more than 100 patients, including pregnant women, a new report by an international rights group says, accusing security forces of crimes against humanity in trying to destroy populations associating with opponents of President Joseph Kabila’s government.

Testimonies from Congolese who fled to neighboring Angola during months of violence earlier this year said Congo’s security forces carried out targeted attacks against the Luba ethnic group that killed hundreds of people in the central Kasai region, the International Federation for Human Rights report says.

The unrest in the once-peaceful Kasai region is a concerted scheme by Kabila to retain power “through chaos and diversion,” the report says. The violence that erupted between another militia group, the Kamwina Nsapu, and Congolese forces after the killing of the group’s leader in August 2016 has widened to reflect tensions over Kabila’s stay in office beyond his mandate as presidential elections are delayed.

The violence in the Kasai region has been called one of the world’s most overlooked crises, with well over a million people displaced and hundreds of thousands of children said to be facing starvation. The Catholic church months ago reported more than 3,300 deaths, and the United Nations has reported at least 87 mass graves.

The new report adds to allegations that Congolese forces have been behind much of the violence. It says the Bana Mura militia attacked a dozen villages this year, using machetes and gunfire, with the support of Congo’s army and police.

“Their level of organization and planning reveals a deliberate strategy of terror and destruction,” the new report says. “The cruelty of the abuses leaves little doubt as to the aim pursued: to terrorize, destroy and force the Luba populations to flee, accused of complicity in the crimes committed by the Kamuina Nsapu militia and of supporting the opposition to Joseph Kabila’s regime.”

There was no immediate response from Congo’s government.

Congolese interviewed for the new report said that between March and August they saw villages destroyed by heavy artillery, hospitals and places of worship attacked and people executed, tortured and mutilated.

In the village of Cinq, where some 10,000 Congolese once lived not far from Angola’s border, Congolese army and police reportedly encouraged the Bana Mura militia as it killed hundreds, including hospital patients and medical staff, the report says.

Survivors reported being pursued all the way to the border as they fled through the bush.

The International Federation for Human Rights says it has a confidential list of 50 Congolese army, police and intelligence service members and Bana Mura militia members suspected of committing crimes and will make it available to “any commission of inquiry or judicial body charged with an independent and impartial investigation.”

The group calls on Congolese authorities to “put an end immediately to the serious human rights violations committed in Kasai.”