(CNN) -- Fighting between rebel forces and local Mai Mai fighters forced the U.N. peacekeeping mission in the Democratic Republic of the Congo to evacuate a dozen aid workers Tuesday from near Rutshuru, in eastern Congo, U.N. officials said.
The workers were brought to an area outside the fighting zone, mission spokeswoman Sylvie van den Wildenberg said.
According to the United Nations' Web site, the fighting was taking place in the village of Kiwanja, less than two miles outside Rutshuru.
The dozen included U.N. workers, said Madnodje Mounoubai, spokesman for the mission. He said they had arrived in the Rutshuru-area Monday.
As of 9 p.m., the fighting between rebels led by Gen. Laurent Nkunda and Mai Mai fighters had not let up, Mounoubai said.
Earlier Tuesday, the International Committee of the Red Cross called the situation in the Rutshuru-area still "unstable."
The fighting comes amid a weeklong cease-fire that Nkunda declared on October 29.
His Congolese rebel forces had launched a renewed bout of heavy fighting in North Kivu last month, displacing thousands of residents from villages and camps throughout the province.
Nkunda is the leader of the National Congress for the Defense of the People (CNDP).
"We want security. We want to have a national army and a strong army who can secure his people. ... We want to have a stable economy," Nkunda said in a recent interview with CNN affiliate Channel 4 in London.
"If I can get it by talks, it can be a good way. But if not, we are ready to give our blood."
Meanwhile, the cease-fire appeared to be holding in Goma -- the capital of North Kivu province -- the United Nations said.
According to a 2002 letter written by then-U.N. Secretary-General Kofi Annan to the president of the Security Council, the term Mai Mai fighters refers to "community-based fighters who come together to defend their local territory."