M23 rebels have launched an attack on Uvira, the last government-held city in eastern DR Congo's mineral-rich region. The fighting has caused thousands to flee across the border into Burundi. Residents and military sources reported sporadic gunfire and explosions as soldiers reportedly fled the city. Shops and schools are closed, and locals fear the rebels have seized some government buildings. South Kivu Governor Jean-Jacques Purusi called reports of rebel control "completely unfounded rumours" and said government forces still hold Uvira. However, local sources told media the rebels patrolled central Uvira at night while the city stayed deserted. A local rights official warned of a "risk of a massacre" if soldiers resist strongly. The rebels advanced from the north near the Burundi border. The US, EU, and eight European nations accused Rwanda of backing the rebel offensive. Rwanda denies involvement and blames DR Congo and Burundi for breaking ceasefire agreements. UN experts say Rwanda’s army controls M23 operations. The conflict has forced about 200,000 people to flee their homes since early June, with at least 74 killed mostly civilians. Over 8,000 refugees crossed daily into Burundi in recent days. This attack follows last year's M23 capture of Goma and Bukavu, two other major eastern cities. M23 is not part of the US-brokered peace deal between DR Congo’s President Félix Tshisekedi and Rwanda’s President Paul Kagame. Talks with M23 continue separately under Qatar’s mediation. Tshisekedi accused Rwanda of "deliberate violations" and called the fighting a "proxy war" over DR Congo’s valuable mineral areas. Rwanda accused DR Congo and Burundi of bombing villages near its border, forcing civilians into Rwanda. Eastern DR Congo has faced violent conflicts for over 30 years, with many armed groups competing for power and wealth in the region. Several peace deals since the 1990s have failed. The current clashes risk destabilizing the entire region.