People stand by and look at United Nations armoured vehicles Thursday as they patrol in the streets of Goma in eastern Congo. The governor of Goma, Julien Mpaluku, acknowledged Wednesday that panic was spreading but stressed that U.N. peacekeepers were still in charge and rebels had not yet entered the city.

Kibati, Congo ? The refugees watched in anger as the U.N. tanks headed away from the battlefield and the Tutsi rebels they were supposed to be stopping.

“Where are they going? They’re supposed to protect us!” shouted Jean-Paul Maombi, a 31-year-old nurse who had fled his village because of the violence. Nearby, young men hurled rocks at the U.N. troops.

The quick unraveling of the world’s largest U.N. peacekeeping effort has come as no surprise to the mission’s critics, who complain the force was unprepared for its main task – protecting civilians from the war.

Growing numbers of civilians are furious at the U.N’s failure to keep them safe. Angry Congolese have pelted rocks at all four U.N. compounds in the provincial capital of Goma. One such attack on the disputed road north of the city critically wounded an Indian officer.

U.N. Secretary-General Ban Ki-moon said Wednesday that peacekeeping troops in Congo are “doing everything possible to protect civilians and fulfill their mandate in untenable circumstances.”

Fewer than 6,000 of the mission’s 17,000 troops are deployed in North Kivu, the site of the current fighting, because unrest in other provinces has required their presence elsewhere, the U.N. says. By comparison, rebel leader Laurent Nkunda commands about 10,000 fighters.

Alan Doss, the top U.N. envoy in Congo, said the U.N. troops have performed “really with great distinction,” but are stretched to the limit and need reinforcements quickly.

The inability to protect civilians is particularly frustrating for the U.N. mission in Congo, which got a strong mandate, including the power to use force, in part because of lessons learned in Rwanda, the former Yugoslavia and other regions of Congo, where failure to prevent civilian killings became a mark of shame.

The explosion of violence in eastern Congo has shown the mission to be lacking more than manpower, however. It has been ill-equipped to deal with the guerrilla tactics of rebels who overwhelm the conventionally trained peacekeepers with hit-and-run attacks by small groups of fighters who hide among civilians in Congo’s dense tropical forests.

The mission is comprised mostly of troops from India, Pakistan, Bangladesh, Uruguay and South Africa. Few speak the region’s languages: the French of its Belgian colonizers, the Kiswahili that is the lingua franca in east and central Africa, or the local tongues of Kinyarwanda or Lingala.

“It’s not just the language skills – it’s about the conflict preparedness, the ability to understand the political situation” said Alex Vines, director of the Africa program at the Chatham House think tank in London.

Perhaps most fundamental is the complexity of the mandate handed to the force, known by the French acronym MONUC. The peacekeepers have been charged with simultaneously protecting civilians, disarming rebel fighters and policing buffer zones separating the insurgents from government troops.

“I think the sense is that they’ve really been hung out to dry,” said Erin Weir, the peacekeeping advocate in Goma for Washington-based Refugees International. “The U.N. Security Council handed MONUC an exceptionally complex set of tasks to accomplish, but never came through with the resources or the political support to get the job done.”

The mission also has been charged with supporting a ragtag Congolese force of 30,000 soldiers cobbled together from a defeated national army and several of the rebel groups who vanquished it in 1996.

“Our mandate tells us to support an army that doesn’t exit,” one U.N. official told The Associated Press recently, speaking on condition of anonymity because he was not authorized to talk to the media. “There is no coherent army.”

A tank from the Congolese army careened into a wave of refugees fleeing fighting near Goma this week, killing three teenagers just down the road from a camp of Indian peacekeepers.

Unaware of the accident, the peacekeepers took no action as thousands of refugees streamed down the road past their base.

“Where are the ‘Blue Helmets?”‘ the refugees demanded to know, referring to the peacekeepers’ distinctive headgear.

When the U.N. troops learned of the accident from AP reporters at the scene and drove with them to investigate, they were stoned by angry civilians and forced to turn back before they reached the hastily dug graves of the victims.