Local politicians on Sunday said Rwanda-backed M23 rebels have seized a strategic eastern town near the provincial capital, Goma, in the Democratic Republic of Congo.
The Tutsi-led M23 group has been waging a renewed insurgency in eastern Congo since 2022.
Congo and the United Nations had accused neighbouring Rwanda of backing the group with its own troops and weapons.
Rwanda says it has taken what it calls defensive measures.
Fighting has flared in recent weeks, leading to territorial gains for M23, which is now in control of Masisi, a town and local administrative centre about 80 km (50 miles) from Goma, provincial parliament member Alexis Bahunga told Reuters.
“The government will take measures to restore state authority over the entire territory,” he said.
Another parliamentary deputy, Jean-Pierre Ayobangira Safari, said Masisi had been taken “for now”.
An army spokesperson declined an immediate comment.
Corneille Nangaa, leader of the anti-government Congo River Alliance (AFC), which includes M23, said rebel forces had reached the centre of Masisi mid-afternoon last week Saturday.
The advance and continued fighting in defiance of a ceasefire agreement further undermined efforts to curb the conflict.
A rare high-level meeting between the Congolese and Rwandan presidents was postponed in December, dashing hopes of a deal to curb the violence that has displaced more than 1.9 million people.
The head of an international organisation working in Masisi said staff members there were in shock and unable to continue operations as businesses were closed, making it hard to source supplies.
“They don’t know how to leave the town since we fear that the … (Congolese forces) will launch a counteroffensive,” the source said, speaking on condition of anonymity.
