KHARTOUM, Sudan, Aug. 6 (UPI) -- The United Nations said Wednesday six people were killed during a violent attack on a civilian convoy in the Darfur region of Sudan.

The civilian convoy was traveling in North Darfur from Nyala to El Fasher when it was attacked by militant rebels, the U.N.-African Union peacekeeping mission reported.

The attack, which happened Monday, also left 28 people injured in a region where recent violence is threatening an already fragile security situation, the United Nations reported.

Officials say there were seven vehicles that were attacked by "unknown men on camels, suspected to be Janjaweed militia," the release said.

Eight people were evacuated by helicopter and taken to a hospital in El Fasher. Officials say most of the other wounded individuals were taken to Nyala for treatment.

The attack came after the U.N. Security Council recently announced that peacekeeping operations in Darfur would be extended by another 12 months.