Rwandan-supported rebels advanced into the periphery of the strategic city of Uvira in eastern Congo on Tuesday, according to local officials, as part of a new offensive that the U.N. reports has displaced over 200,000 residents in recent days.

This latest assault by the Rwandan-supported M23 rebel faction occurs despite a peace agreement mediated by the U.S. that was signed last week by the presidents of Congo and Rwanda in Washington.

The agreement did not involve the rebels, who are in separate negotiations with Congo and had previously consented to a ceasefire earlier this year, which both parties accuse each other of breaching.

However, the accord mandates Rwanda to cease its support for armed groups and to work towards ending hostilities.

Marafiki Masimango, a representative of Uvira's civil society, reported that rebels were advancing south into the city of South Kivu late Tuesday, and that some government soldiers tasked with protecting the city had deserted.

He mentioned that residents were in a state of panic and that he himself had to flee before nightfall.

If the remaining soldiers offer significant resistance, then "there's a danger of a massacre, and numerous individuals will die," stated Masimango.

John Kashwinze, the secretary to the mayor of Uvira, refuted claims that M23 rebels were present in the city late Tuesday night.