IF UN forces take a tough line in intervening between rebels and government forces in the Democratic Republic of Congo, it could put both civilians and aid workers at risk, relief organisations said this week.

In a new tactic, the UN has sent a 3000-strong brigade to the eastern region of the country, with instruct-tions to "neutralise" armed groups in a security zone established around Goma, the capital of North Kivu province. The US has given fighters 48 hours to disarm.

A spokesman for the UN peacekeeping force MONUSCO, Charles Bambara, said that it was a test "to see how this kind of force could help in protecting civilians . . . the key mission for all peacekeeping operations. It will act as a deterrent force, and be another tool to help bring about peace, alongside efforts to reach a negotiated settlement of the conflict."

Christian Aid's humanitarian director, Nick Guttman, said: "The danger is that our partner staff will not be able to operate as freely as they can do, because they may be perceived to be linked with the [brigade] . . . and we'll potentially be targeted."

Tariq Riebl, Oxfam's humanitarian programme co-ordinator in Congo, said: "The UN must ensure that its operations do not make a bad situation much worse."

But Yvon Edoumou, a UN spokesman in Congo said: "So far the brigade has not impacted on our ability to deliver food, aid, water, medicine. Let's see what happens."

This week, Christian Aid reported that new fighting north of Goma had forced more than 4200 people to flee. In addition, recent attacks by another rebel group, the ADF-Nalu, around Beni, North Kivu, caused an estimated 66,000 people to flee into Uganda.

The Christian Aid senior policy and advocacy officer, Chantal Daniels, said: "The impact of the current fighting on local populations and displaced people close to the front lines is disastrous."