Fighting between the mostly Tutsi M23 rebellion and DRC government forces has flared in recent days around the town of Sake, 20 kilometers (12 miles) from Goma in North Kivu province.
The DRC, the UN and Western countries say Rwanda is supporting the rebels in a bid to control vast mineral resources, an allegation Kigali denies.
Several dozen demonstrators, some draped in the DRC flag with red bands around their heads, trampled on the flags of the United States, the European Union, France and Poland.
"We are in the street to denounce the crimes of which the Congolese are victims," Espoir Mwinuka, an activist with the Lucha (Struggle for Change) movement, told AFP.
"Rwanda kills us every day and is supported by the international community, which is why we burned these flags," he added.
They carried placards, reading: "Stop the massacres in the DRC," "France = M23/Rwanda," "To be silent is to be an accomplice."
The demonstrators, mainly young men, marched from the city center to the road leading to Sake before turning back.
Dozens of soldiers and civilians have reportedly been killed or wounded in the latest fighting, which pushed tens of thousands of civilians towards Goma.
On Saturday, the DRC army accused Rwanda of using "drones" to attack Goma airport.
The demonstration was banned by Goma's city hall but took place peacefully, with no clashes between police and army forces.
Militias have plagued the eastern DRC for decades, a legacy of regional wars fought in the 1990s and the early 2000s.
Anti-Rwanda Protests Erupt in Eastern DRC
GOMA - Anti-Rwanda demonstrators burned Western countries' flags Monday in the city of Goma in eastern Democratic Republic of Congo, accusing them of supporting Kigali through the M23 rebels, an AFP journalist saw.
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