Kigali's response to the DRC demonstrations in Goma and Kinshasa's ambassador recall was to term the moves DRC's effort to distract from its own security failures.
DRC's government decided to expel Rwanda's ambassador on Saturday. Rwanda stated that it had noted the decision "with regret".
Monday, DRC protesters chanted for weapons to fight Rwanda, as well as slogans hostile to Uganda, which some also accuse of backing the M23.
"We denounce the hypocrisy of the international community in the face of Rwanda's aggression," said Mambo Kawaya, a civil society representative attending the demonstration.
The crowds threw stones and also targeted the empty offices of the International Conference on the Great Lakes Region, an inter-governmental group that includes Congo and Rwanda. There, they tore down posters and burnt a photo of Rwandan President Paul Kagame.
"We have suffered a lot because of the war against the M23 and we know that if there is a country that supports them, it's Rwanda," said protester Masango Murefe Moise.
Rwanda denies Congo's long-standing accusations that it backs M23.
Despite official denials from Kigali, an unpublished report for the United Nations seen by AFP in August pointed to Rwandan involvement with the M23.
The same report said the M23 plans to capture Goma, an important trade hub of about one million people, to extract political concessions from the Congolese government.
A mostly Congolese Tutsi group, the M23's resurgence has destabilized regional relations in central Africa, with the DRC accusing its smaller neighbor Rwanda of backing the militia.
The M23 resumed fighting in late 2021 after lying dormant for years, accusing the Democratic Republic of Congo's government of failing to honor an agreement to integrate its fighters into the army.
Rebels in recent days seized the towns of Kiwanja and Rutshuru, along a strategic highway leading to the provincial capital Goma, which lies on the Rwandan border.
Goma, the capital of North-Kivu, has been effectively cut off from the upper half of the province since the capture of Kiwanja. At least four civilians have been killed and more than 35,000 people forced to flee their homes since fighting resumed on Oct. 20.
The recent M23 attacks broke months of relative calm since the group's last major offensive in late May - the most serious since a 2012-2013 insurrection that seized vast swathes of territory before fighters were chased out by Congolese and United Nations forces into Uganda and Rwanda.
Rwandan President Paul Kagame tweeted on Monday that he had held a discussion with UN chief Antonio Guterres on how to de-escalate.