The rebels advance comes less than a week after Congolese President Felix Tshisekedi and his Rwandan counterpart Paul Kagame affirmed their commitment to a U.S.-brokered peace deal.

A commuter rides on the back of a motorbike as pedestrians walk along a road in Uvira, Democratic Republic of Congo, on Tuesday.AFP - Getty Images

Rwanda-backed M23 rebels have entered the eastern Congo town of Uvira, an important base for the Congolese army near the border with Burundi, four sources including two residents told Reuters on Wednesday.

Uvira, situated on the shores of Lake Tanganyika, has served as the headquarters of the Kinshasa-appointed government in South Kivu after the province`s capital, Bukavu, fell to M23 in February. It has also served as the regional military base and M23`s seizure of the town could allow it to advance on other sites beyond South Kivu.

The latest milestone in the rebels` advance through the mineral-rich region comes less than a week after Congolese President Felix Tshisekedi and his Rwandan counterpart Paul Kagame met with President Donald Trump in Washington and affirmed their commitment to a U.S.-brokered peace deal.

President Donald Trump hosts Democratic Republic of Congo President Felix Tshisekedi, left, and Rwandan President Paul Kagame in Washington earlier this month. Chip Somodevilla / Getty Images

Rwanda denies backing M23 in Congo, saying its troops are in eastern Congo for "defensive measures," although Washington and the United Nations say evidence of Rwandan support for the rebels is clear.

"The city of Uvira is now liberated," Lawrence Kanyuka, spokesperson for a coalition that includes M23, said on X.

The decision to take the city was motivated by months of attacks by Congolese and allied forces, he said.

It was not clear on Wednesday afternoon whether M23 was fully in control of Uvira, as residents reported hearing gunfire.

However a Congolese government source told Reuters that the military would not react, in order to protect civilians.

Reuters reported on Monday that M23 had captured Luvungi, a town that had stood as the front line since February, and that fierce fighting was ongoing near Sange and Kiliba, villages further along the road towards Uvira from the north.

On Tuesday the U.S. and nine other members of the International Contact Group (ICG) for the Great Lakes voiced "profound concern" over the renewed clashes in South Kivu province, where Uvira is located, warning that the violence could destabilise the wider region.

Burundi`s foreign minister, Edouard Bizimana, told Radio France Internationale on Wednesday that his country had registered more than 30,000 refugees from Congo in the past three days.