KIGALI/WASHINGTON - Rwanda on Saturday denied U.S. accusations that its forces attacked a displaced persons' camp in eastern Democratic Republic of Congo (DRC) and instead blamed militias it said were supported by the Congolese military for the assault.

The U.S. strongly condemned Friday's attack which killed at least nine people, the U.S. State Department said in a statement.

The attack was mounted from positions held by the Rwandan Defense Forces (RDF) and the Rwanda-backed M23 rebel group, the U.S. statement said. The U.S. is "gravely concerned about the recent RDF and M23 expansion" in eastern Congo, it said.

Rwandan government spokesperson Yolande Makolo denied the RDF was behind the attack and instead blamed it on militias supported by the Congolese military.

"The RDF, a professional army, would never attack an IDP (displaced persons). Look to the lawless FDLR and Wazalendo supported by the FARDC (Congolese military) for this kind of atrocity," she said in a post on X.

The Democratic Forces for the Liberation of Rwanda (FDLR) is a Hutu group founded by Hutu officials who fled Rwanda after orchestrating the 1994 genocide while Wazalendo is a Christian sect.

A two-year offensive by M23 rebels has moved closer to the eastern Congolese city of Goma in recent months, prompting thousands to seek refuge in the city from surrounding areas.

(Reporting by Eric Beech, Additional reporting by Philbert Girinema in Kigali; Writing by Elias Biryabarema; Editing by Angus MacSwan)