Rebel fighters from the M23 movement pushed into Uvira on Wednesday, breaching the last major government stronghold in eastern DR Congo and triggering a new wave of displacement into Burundi, according to residents. Witnesses reported heavy shelling around the city and described a “chaotic” situation as thousands sheltered indoors.

Despite recent US-brokered talks between Congolese President Félix Tshisekedi and Rwanda’s Paul Kagame, the offensive continued to gain ground. M23 announced it had “liberated” Uvira, and locals told UN-backed media that fighters were positioned on key roads. South Kivu Governor Jean-Jacques Purusi, however, maintained that government forces and allied militias were still holding the city.

Residents said rebel columns entered from the northeast without facing resistance, prompting some civilians to cheer. The city quickly went into lockdown, with one witness warning: “Three bombs have just exploded in the hills. It's every man for himself,” while another said: “We are all under the beds in Uvira - that's the reality.” A local rights advocate cautioned there was a “risk of a massacre” if government troops attempted to retake territory.

Security sources reported that Congolese forces had already fallen back toward Swima, Makobola, and Baraka. Rebel presence was also reported in neighborhoods where pro-government Wazalendo militiamen attempted to hold ground.

The escalation has strained regional relations. Burundi, which has several thousand troops deployed in eastern DR Congo, accused the M23 advance of undermining Washington’s peace efforts. Foreign Minister Edouard Bizimana called the rebel gains “a slap in the face... a middle finger” and added that “Signing an agreement and not implementing it is a humiliation for everyone, and first and foremost for President Trump.”

The US, EU, and multiple European governments issued a joint warning expressing “profound concern” and urging the Rwanda Defence Force to “immediately halt offensive operations” and withdraw. Rwanda rejected the accusations, insisting the ceasefire breach “cannot be placed on Rwanda” and accusing Congolese and Burundian forces of bombing villages near its frontier.

Humanitarian agencies say roughly 200,000 people have fled since the latest fighting began, with dozens of civilian deaths reported. Burundian officials have documented tens of thousands of new arrivals at the border in recent days.

Uvira had served as South Kivu’s temporary administrative center after M23 captured Bukavu earlier this year. The group, which resurfaced in 2021 after nearly a decade of relative inactivity, previously seized Goma and Bukavu in last year’s rapid expansions. Though not a party to the US-brokered accord, M23 remains in separate negotiations mediated by Qatar.

In a national address, Tshisekedi accused Rwanda of “deliberate violations” and described the conflict as “a proxy war aimed at challenging our sovereignty” over a region rich in strategic minerals. Rwanda, for its part, said Congolese and Burundian forces had driven more than 1,000 civilians across its border.

The latest capture of Uvira came just hours after the International Contact Group for the Great Lakes called on both M23 and the Rwandan army to “immediately halt” operations in eastern DR Congo.