Clashes broke out Monday near the eastern city of Goma on Monday, just days before United Nations Secretary General Ban Ki-moon is set to arrive in the Democratic Republic of Congo, according to Al Jazeera.
The violence is the first major flare-up reported near the city in nearly six months, said Al Jazeera, describing fierce clashes between Congolese forces and rebel fighters.
"The fighting has been with heavy weapons. It's still continuing although it is less intense ... We're sending reinforcements. We must protect the town of Goma at all costs," Colonel Olivier Hamuli said, according to Reuters.
Goma is a mineral-rich city that was taken over by the the Tutsi-majority M23 rebels for a period of time last year. They withdrew in December.
M23 spokesman Amani Kabasha told Agence France-Presse Monday's fighting broke out just north of the city. There were no immediate reports of fatalities.
Monday's clashes put an end to troubled peace talks between the two parties, said Reuters, noting that Tanzanian troops tasked with "neutralizing" groups like M23 had also recently arrived in the area.
The UN chief is set to arrive on Wednesday in order to highlight the decades-long violence gripping the nation.
It remains unclear whether or not his itinerary, which reportedly includes time in Goma, will change in light of the unrest.