The group of about 1,000 fighters created after several officers from the Congolese army defected in April and May, has been fighting the Congo army south of its base in Rutshuru for two months. It is now spreading its control toward Lake Edward.

The rebels took the small town of Nyamilima on Monday and now say they are planning to attack Ishasha, a trading post on the border with Uganda.

The M23 said that they are attacking to protect the local population from other rebel groups such as the Mai Mai and the FDLR.

"The population asked us to come because they were suffering at the hand of the Mai Mai defense groups and the FDLR," said Col. Vianney Kazarama. "If we need to go further than Nyamilima and Ishasha, we will."

The FDLR is a Hutu armed group that was created after the 1994 Rwandan genocide when Hutu militias that took part in the killing left the country and regrouped in Congo. For the past 18 years the Hutu militia have operated in eastern Congo.

The M23, made up principally of Tutsis, is determined to battle the FDLR and Mai Mai, said spokesman Vianney Kazarama.

Although the M23 controls the town of Nyamilima, they do not completely control the road to the north, where Mai Mai defense groups and FDLR roam the area and stop cars.

Kazarama said the M23 is also trying to forge an alliance with several of the Mai Mai defense groups to bring "discipline" to the combatants and to fight the FDLR and the government together. But Mai Mai groups are reluctant to ally with an armed group they perceive as foreign because of its ties with Rwanda. In June, the United Nations group of experts on Congo released a report accusing Rwanda of supporting the M23. The government has denied any support.

Ishasha residents have been living under different armed groups for two years, since the Congolese army left the area.

"Sometimes the FDLR control, sometimes it is the Mai Mai," said 20-year-old Janine Rensaro.

Now, the population in Ishasha has begun to flee across the border to Uganda with fears of fighting between the M23 and the local Mai Mai groups.

"For a week there have been a lot of troubles. We had to flee because we fear atrocities will be committed if the M23 comes," said Rensaro.

Border customs official Lumesa Kibukila said everyone has fled since they hear that M23 had taken Nyamilima. Even police and local authorities have taken refuge in Uganda, he said.

More than 3,000 refugees have been registered in the Matanda transit center in Uganda, according to authorities there who said there are another 500 Congolese in Uganda who are not registering with the camps as they wait to see what happens in their hometown of Ishasha.

A week ago, armed men shot and burned civilians 5 kilometers (3 miles) from Ishasha, and five dead bodies and six wounded civilians were brought to a hospital in Nyamilima after the attack.

Both M23 and local Mai Mai defense groups say they are planning attacks on Ishasha and Nyamilima respectively to try gain full control of the area, according to the M23 and Mai Mai spokesmen.

M23 spokesperson Kazarama said Goma, the capital of North Kivu located south of Rutshuru, remains the group's main front and its priority.

A series of murder and violence in Goma, apparently perpetrated by elements of the Congolese army posted around the city, have led to renewed M23 threats that they will take the town if the government "cannot secure its population," he said.

It remains uncertain whether the M23 can hold on two fronts at the same time without spreading their forces thin. In Nyamilima, around 25 rebel soldiers are patrolling the town, while Mai Mai and FDLR are still on the road between the two M23 positions in Kiwanja and Nyamilima.