About 200,000 people have fled their homes in the eastern Democratic Republic of the Congo (DRC) in recent days, the United Nations says, as Rwanda-backed rebels swarm a strategic town just days after a United States-led peace effort, which now appears under severe threat.The M23 armed group pushed into the outskirts of the strategic city of Uvira in South Kivu province on Tuesday, local authorities said, as part of a new offensive in which at least 74 people had been killed, according to the UN.Recommended Stories list of 4 itemsend of listThe latest fighting comes despite a US-mediated peace agreement signed last week by the Congolese and Rwandan presidents in Washington, DC. The accord did not include the rebels, who are negotiating separately with the DRC and agreed earlier this year to a ceasefire that both sides accuse each other of violating, but it obliges Rwanda to halt support for armed groups.Despite the renewed fighting just beginning on Monday, the M23 has managed to capture several strongholds, including Uvira now, “a big gain”, said Al Jazeera’s Alain Uaykani, reporting from Goma, the biggest city in the eastern DRC.Uvira has not just been a military base but also the administrative place for the government since they were chased out from the town of Bukavu in January, he said.“So it was almost like a stronghold of the government position, from where they reorganised themselves,” Uaykani said, adding that it was also a place the government was hoping to chase out the rebels from.“There is no DRC army in sight because the majority of them too …