"Initial reports suggest two peacekeepers are dead and several more have been wounded," said U.N. spokesman Stephane Dujarric, adding that the injured have been evacuated to Goma.
"The mission deployed attack helicopters as well as the force intervention brigade in support of operations as well as to reinforce presence," he said, adding that mission forces are also deployed to restore order and protect the population.
The suspected rebels attacked early Monday near a UN base in Mamundioma, about 35 kilometers (22 miles) from Beni, UN Congo mission spokeswoman Florence Marchal said today.
Some weapons were seized by the rebels in their Monday raid, said Jean-Paul Ngahangondi of a local civil rights group.
A Tanzanian brigade is stationed at the U.N. base there where in an earlier incident in September ADF rebels killed a Tanzanian peacekeeper.
Ten people were killed in fighting in the region Saturday night, said local administrator Amisi Kalonda. At least 22 people are missing, said David Muhaze, the president of a civil society organisation. The total of missing and dead could not be confirmed by officials.