M23 confirmed the renewed fighting on Tuesday, following a similar announcement by the Congolese Army on Monday.
In a statement, the army said it occasioned heavy losses on the rebels in the Lubero territory of North Kivu province leaving several dead and others wounded.
The latest fight comes after a ceasefire deal signed in July and which came into effect in August.
It also comes a few days after foreign ministers of Congo and Rwanda agreed on the terms and conditions of the disengagement of those Rwandan forces in the region.
On November 30, the rebels said they were upholding a ceasefire agreed in March 2023 despite not being involved in talks between Rwanda and Congo.
The resumption of fighting comes amid a planned meeting between DRC President Felix Tshisekedi and his Rwandan counterpart Paul Kagame on December 15.
It would be their first official meeting since last year. DRC and the United Nations accuse Rwanda of backing M23.
Rwanda, however, denies the claim only maintaining that it has troops in the region for its security.
The eastern part of DRC has been insecure for many years, including during the civil wars in the 1990s.
There are multiple armed groups operating in the provinces of Itari, North Kivu and South Kivu.
M23 rebels reemerged in 2021 after it had been defeated in 2013.
There are two diplomatic initiatives currently underway to end the fights in the country that have left thousands of civilians displaced.
The Nairobi Process was brokered by the East Africa Community (EAC) in November 2022 and focuses on armed groups. Angola is mediating the Luanda process, which focuses on relations between the DRC and Rwanda.
In July 2022, Angola, DRC, and Rwanda signed the Luanda roadmap for peace in eastern DRC.
On July 30 this year, the DRC and Rwanda signed a cease agreement (PDF) mediated by Angola.
