The resolution gave the 2,500-troop force orders to "neutralize" and "disarm" armed groups in the east of the country. The brigade and surveillance drones to monitor the Democratic Republic of Congo's borders will be operating by July, UN officials said.

The force will act "in a robust, highly mobile and versatile manner and in strict compliance with international law," according to the resolution, to "prevent the expansion of all armed groups, neutralize these groups, and to disarm them."

The brigade will comprise three infantry battalions, one artillery and one special forces and a reconnaissance company with headquarters in Goma, the North Kivu provincial capital. The UN campaign aims to end conflict in Democratic Republic of Congo's border regions with Rwanda and Uganda.

Rwanda - a temporary member of the Council - and Uganda have been accused of backing the M23 rebels who briefly took Goma in November. Both countries have denied the charges.

Some reservations

The mandate to conduct "targeted offensive operations" is the first of its kind.

Guatemala, a Council member that has troops in Democratic Republic of Congo, "wavered" over backing the resolution, said Gert Rosenthal, its UN envoy. Several countries fear that the offensive brigade will make other peacekeepers targets.

Pakistan’s UN ambassador, Masood Khan, also stressed that the intervention brigade should be a one-off operation.

mkg/dr (AFP, AP)