Burundi has closed its border with the Democratic Republic of the Congo (DRC) after the March 23 Movement (M23) rebels advanced into Uvira, a strategic city in eastern DRC located near Burundi’s economic capital, Bujumbura, Congolese security sources said Wednesday.

The M23 said in a statement that its fighters have entered Uvira. “We confirm that the city of Uvira is now liberated,” M23 spokesperson Lawrence Kanyuka posted on X, urging residents to resume their activities calmly.

However, the Armed Forces of the DRC (FARDC) dismissed the claim as “a diversion” intended to cause panic. “The city and its surroundings remain under the control of the loyalist army,” said regional FARDC spokesperson Mbuyi Kalonji Reagan, calling on residents to remain calm and vigilant.

Uvira, the second-largest city in South Kivu Province, has served as a temporary administrative center since the province’s capital, Bukavu, was taken over by the M23 earlier this year. Bordering Burundi, Uvira is a key commercial hub and a gateway to the Great Katanga region, one of the DRC’s main economic zones.

Between Dec. 5 and 9, nearly 38,000 asylum seekers crossed from the DRC into Burundi to escape insecurity in the east, Burundi National Radio and Television reported Wednesday.