The UN Security Council on Saturday demanded an end to the recent escalation of violence in the eastern Democratic Republic of the Congo (DRC), where hundreds of civilians were killed and yet another town in eastern Congo was seized by rebels.

The rebels launched a pre-dawn raid on the town of Kibumba in North Kivu on Saturday, prompting the UN to dispatch attack helicopters at dawn for defense and hold an emergency meeting to discuss the surging violence.

The rebels were last reported just 18 km from the provincial capital of Goma. Officials fear it is now under threat of attack.

"The members of the Security Council express deep concern regarding the rapidly deteriorating security and humanitarian crisis in the eastern DRC due to the ongoing military activities of the 23 March Movement (M23)," Indian UN Ambassador Hardeep Singh Puri, president of the 15-nation Security Council for November, said in a statement issued after the meeting.

The rebel group, known as M23, is composed of a breakaway faction of soldiers from the DRC's national army. It recently seized seven towns in North Kivu province and ramped up attacks on schools, hospitals, homes and other civilian targets.

More than 260 civilians had been killed, including 83 children, earlier this week, UN officials said.

The eastern DRC provinces of North and South Kivu have recently witnessed intensified fighting between government troops and the M23, which has displaced more than 100,000 people and forced many to fled to neighboring Rwanda and Uganda.

"The members of the Security Council strongly condemn the resumption of attacks by the M23 and demand their immediate cessation as well as the cessation of any further advances toward the city of Goma," he said.

"They express their intention to apply additional targeted sanctions against the leadership of the M23 and those acting in violation of the sanctions."

Ladsous said despite the deployment of government troops and helicopters, Kibumba still fell into the hands of the M23. The government and UN peacekeepers were on standby to ward off further rebel advances, he said.

"Needless to say, the humanitarian consequences of the fighting are devastating," Ladsous said.

Some 4,000 homeless refugees have gathered at a refugee camp that has already housed between 60,000 and 80,000 people. The camp, just five km from the rebels, would no longer be considered as a safe place once the M23 advances further and these people will flock toward Goma to seek protection, he said.

The pre-dawn attack on Kibumba suggested that the M23, thought to be short of night-fighting capabilities, have acquired night-vision goggles and heavy mortars, UN officials said.

Rwanda has long been accused of supporting the M23, but the council has not named the country on the ground of insufficient "hard evidence" to support the allegations.