NAIROBI: Hundreds of furious protesters hurled rocks at a United Nations compound in eastern Congo on Monday in frustration that peacekeepers have not halted the rebel advance that is sweeping the countryside.

The rebels are now in control of several major towns and the headquarters of a national park where endangered mountain gorillas live in the middle of a shrinking ring of safety.

Jaya Murthy, a spokesman for Unicef in the eastern Congo city of Goma, said heavy fighting was raging in several areas between government troops and rebel forces under the command of Laurent Nkunda, a renegade general who says he is fighting to protect ethnic Tutsis.

Murthy said that the conflict was spawning a vast wave of internally displaced people, with tens of thousands fleeing battle zones, often for the second or third time in recent months. As many as 250,000 people have been driven from their homes since the fighting between the rebels and government forces intensified in August.