Hundreds of people took to the streets of the Congolese capital, Kinshasa, to denounce Rwanda’s alleged backing of the M23 rebel group.
The protests were organised by the civil society group, NDSCI.
On Monday, the chairman of the African Union, the Senegalese President Macky Sall, telephoned the Rwandan and Congolese leaders to try to ease tensions between Kigali and Kinshasa.
Both sides accuse each other of supporting rebel groups in eastern DR Congo.
Mr Sall had earlier expressed “grave concern” at rising tensions between the two countries.
He appealed for dialogue to resolve the dispute.