A military parade by the M23 rebel group in eastern Congo has raised concerns over an impending peace deal between Congo and Rwanda.

LAGOS, Nigeria (AP) — A military parade at the weekend by a rebel group in control of mineral-rich eastern Congo has raised concerns over the future of an impending peace deal between the government and the rebels’ main backers, Rwanda.

The deal will shape the fate of the M23 rebel group in eastern Congo, which launched blitz attacks in January to take over key cities including Goma and Bukavu while the Congolese army swiftly retreated. U.N. experts said the M23 was backed by thousands of troops from neighboring Rwanda.