The UN said in a statement that bombs hit two camps for displaced people in Lac Vert and Mugunga, near the city of Goma, the provincial capital of North Kivu.

The UN called the attacks a “flagrant violation of human rights and international humanitarian law and may constitute a war crime”.

Lt. Colonel Ndjike Kaiko, a Congolese army spokesperson, blamed the attacks on a rebel group, known as M23, with alleged links to Rwanda, in a statement provided to The Associated Press.

The M23 rebel group denied any role in the attacks and blamed Congolese forces in a statement published on X.

Details from the area were still emerging on Friday.

A UN spokesperson, Jean Jonas Yaovi Tossa, told the AP that at least 12 people were killed and more than 20 injured in the attacks.

Save The Children, an aid group, said it was present at one of the camps when shells struck close to a busy marketplace ahead of their vehicle. It said dozens were injured, mostly women and children, and the death toll was still unclear.

Congo's president, Felix Tshisekedi, who was travelling in Europe, decided to return home Friday following the bombings, a statement from his office said.

Tshisekedi has long alleged that Rwanda is destabilizing Congo by backing the M23 rebels. UN experts, along with the US State Department, have also accused Rwanda of backing the rebels. Rwanda denies the claims.

Earlier this week, French President Emmanuel Macron called on neighbouring Rwanda to halt its support for the M23 rebel group during a joint press conference with Tshisekedi in Paris.

The bombings follow the M23 rebel group's capture of the strategic mining town of Rubaya this week.

The town holds deposits of tantalum, which is extracted from coltan, a key component in the production of smartphones. It is among the minerals that was named earlier this month in a letter from Congo's government questioning Apple about the tech company's knowledge of “blood minerals” being smuggled in its supply chain.

The decadeslong conflict in eastern Congo has produced one of the world's worst humanitarian crises, with over 100 armed groups fighting in the region, most for land and control of mines with valuable minerals. Some are fighting to try to protect their communities.

Many groups are accused of carrying out mass killings, rapes and other human rights violations. The violence has displaced about 7 million people, many beyond the reach of aid.