UNITED NATIONS, Dec. 11 (Xinhua) -- UN Secretary-General Antonio Guterres was deeply alarmed by the escalation of violence in the eastern Democratic Republic of the Congo (DRC) as the security situation has sharply worsened since Dec. 2, his deputy spokesperson said Thursday.

"The secretary-general strongly condemns the offensive by the Alliance Fleuve Congo/Mouvement du 23 mars (AFC/M23) in several locations in South Kivu province, including Kamanyola, Luvungi, Katogota and Uvira, which has resulted in civilian casualties," said Farhan Haq.

Guterres called for an immediate and unconditional cessation of hostilities.

The UN chief's plea came a week after U.S.-backed peace accords between the DRC and neighboring Rwanda were signed at the White House. The DRC has long accused Rwanda of supporting the M23 rebel group, an allegation the latter strongly denies.

Haq said Guterres warned that the escalation of violence risks seriously undermining efforts to achieve a sustainable resolution of the crisis and increases the risk of a broader regional conflagration.

The secretary-general urged the parties to abide by their commitments under the Washington Accords for Peace and Prosperity, signed on Dec. 4, and to fully respect the Nov. 15 Doha Framework for a Comprehensive Peace Agreement between the DRC and the M23, according to Haq.

"The secretary-general notes that the United Nations is fully mobilized to work with partners to ensure the delivery of humanitarian assistance to those in need and reiterates his readiness to continue supporting ongoing diplomatic efforts to restore peace in eastern DRC and the region, in line with the Peace, Security and Cooperation Framework for the DRC and the region," Haq said.

The UN Office for the Coordination of Humanitarian Affairs (OCHA) said some families have started returning to areas that are now relatively calm, while the vast majority remain in overcrowded sites, where they face heightened protection risks and increased threats of disease outbreaks, including cholera and mpox.

"Our colleagues say the situation today (on Thursday) is calm in the town of Uvira, though sporadic gunfire persists in several neighborhoods," OCHA said.

On Wednesday, an explosion in the neighborhood of Kimanga reportedly killed two civilians and injured three others. Uvira's main referral hospital continues to receive an influx of wounded people, including more than 60 patients transferred from Ruzizi Hospital, which reportedly ceased operations on Tuesday due to insecurity, said the office.

OCHA said that people continue to flee to the south into the Tanganyika province. Since Monday, at least 27,000 people arrived in Kisongo and Kabimba in Kalemie territory, with additional arrivals reported in Kalemie town and along Lake Tanganyika's shores.

The office said it continues to engage with all parties to facilitate the safe movement of humanitarian teams and to enable the resumption of aid operations. Efforts are underway to pre-position critical stocks, including shelter, water, food, and support for health and protection. Additional funding is urgently needed to provide vital life-saving and protection assistance to newly displaced people.

The humanitarian office said that displaced people from South Kivu continue to arrive in neighboring Burundi. On Wednesday, OCHA coordinated a rapid needs assessment in Burundi's Ndava and Gatumba, where partners and authorities estimated that more than 50,000 people sought safety. The Cishemere transit camp in Burundi is hosting 5,000 people, while Bweru is hosting 1,000, with more people continuing to arrive.

"The refugees -- mainly women and children -- are arriving exhausted and injured," OCHA said. "Despite partners' efforts to scale up the response, conditions at these sites remain very precarious -- and shelter, food, water, hygiene supplies, sanitation facilities, and protection support are urgently needed. However, humanitarians' ability to scale up the response is severely constrained by limited funding."

To make matters worse, the office said, some parts of South Kivu are experiencing a cholera outbreak. OCHA is calling for a scaled-up response in Burundi's Cibitoke and Gatumba areas, which host DRC refugees. The government of Burundi is relocating some refugees to the Bweru site in the eastern part of the country.

The UN Refugee Agency (UNHCR) reported transporting refugees from border points to Bweru by bus and has installed refugee housing units and a water tank to meet basic needs.

In Rwanda, the UNHCR is supporting a government response to assist at the Nyarushishi Transit Centre, including registration, health and nutrition services, protection support, hot meals and other essentials. ■