The United States has held the Rwandan army and the M23 rebel group responsible for the deadly bombing of a camp for displaced people in the Democratic Republic of the Congo.

At least nine people, including seven children, were killed in the raid on Mugunga camp in the eastern city of Goma on Friday.

The Congolese army and the March 23 Movement exchanged accusations of responsibility for the attack.

Rwanda, which borders the Democratic Republic of the Congo, faces widespread accusations of supporting the rebel group, which it denies.

The US State Department said Friday’s attack came from positions controlled by the Rwandan Defense Forces and the M23 group.

A US spokesperson said the United States was “deeply concerned by the recent expansion of the Rwandan Defense Forces and M23” in eastern Democratic Republic of the Congo, and called on both parties to “respect human rights and adhere to applicable obligations under international humanitarian law.”

“It is essential that all states respect each other’s sovereignty and territorial integrity and hold all actors accountable for human rights violations in the conflict in eastern DRC,” they added.

Pictures circulated on social media showed bodies lying on the ground in the camp on Friday.

Most of the residents fled there to escape the fighting in their towns and villages.

Lieutenant Colonel Guillaume Ngeki Kaiko, spokesman for the DRC army in the region, said the strike was in response to previous Congolese attacks on Rwandan army positions.

President Felix Tshisekedi, who spent several weeks abroad, will return to the central African country this weekend after the attack.

Rebel forces and government forces have been accused in recent months of committing abuses against civilians as they compete for control of territory.

Meanwhile, a military court in Goma sentenced eight soldiers from the Democratic Republic of the Congo to death for “desertion” and “cowardice” while fighting rebel forces.

The M23 Movement, formed as an offshoot of another rebel group, began working in 2012 ostensibly to protect the ethnic Tutsi population in eastern DRC, who have long complained of persecution and discrimination.

UN experts said the group was supported by neighboring Rwanda, which is also Tutsi-led, something Kigali has consistently denied.