The East African Court of Justice has started proceedings on a case filed by the Democratic Republic of Congo (DRC) against Rwanda, accusing it of violating its sovereignty and sending troops to support rebel groups in the country’s eastern region.

Eastern DRC has witnessed years of instability as more than 120 armed groups have fought for power, land and valuable mineral resources. The most powerful group is the M23 which the Congolese government – alongside the United States and France – has accused Rwanda of sponsoring. Kigali has denied the allegations.

“DRC accuses Rwanda of acts of aggression that allegedly violate its sovereignty, territorial integrity, political stability, and independence,” read a statement on social media from the Tanzania-based court. “The DRC argues that Rwanda’s actions have led to significant human rights violations in the North Kivu region,” it said.

The proceedings came a day after DRC President Felix Tshisekedi called for sanctions against Rwanda at the UN General Assembly for its alleged support for M23.

The DRC has alleged that Rwandan forces have been involved in aggression and war crimes in the east. In July, UN experts estimated that between 3,000 and 4,000 Rwanda government forces are deployed in eastern DRC alongside the M23, which has been making major advances since 2021 after being dormant for nearly a decade.

The East African Court of Justice, based in Arusha, Tanzania, was established as a regional court under a 1999 treaty among a group of East African nations and is meant to hear cases from Kenya, Burundi, Rwanda, Uganda and Tanzania. The court has been ratified by the UN.

In the lawsuit, Congo seeks to hold Rwanda accountable for violations including atrocities against civilians and breaches of international law, and also secure reparations for the victims of these alleged crimes.

“We are happy the case has taken off,” the lawyer representing DRC, Elisha Ongoya, told The Associated Press.

Rwanda raised objections, questioning the court’s jurisdiction in the case. Its lawyer, Emile Ntwali, urged for the case to be dismissed since the regional court does not handle criminal matters. Ntwali also accused the DRC of failing to translate some of the documents from French to English – the court’s language. The Congolese legal team asked the court to be allowed to submit new evidence and translated documents.

Presiding Judge Yohanne Masara said the court would review each side’s arguments and deliver a ruling on the objections at a later date.

The court case opened as Human Rights Watch released a report accusing both the Rwanda army and the M23 of having “indiscriminately” shelled displacement camps and other densely populated areas in Goma, North Kivu province. The city is eastern DRC’s main hub, and home to some two million people and about half a million displaced people seeking refuge there.

It also accused the Congolese armed forces and allied militias of having increased the risk faced by displaced people in the camps “by deploying artillery nearby and by entering the camps, where they have committed abuses against residents”.

Both sides have also “killed and raped camp residents, interfered with aid delivery, and committed other abuses”, read the report.

At the core of the conflict in eastern DRC is a competition for valuable minerals. The country is home to some of the world’s largest reserves of metals and rare earth minerals like cobalt, considered essential in the lithium-ion batteries that power electric vehicles (EVs). As much as 70 percent of the world’s (PDF) cobalt supply comes from the DRC. Coltan, used in gadgets like PlayStations and phones, is also plentiful in eastern DRC.