U.N. officials have expressed confidence in the overall success for Sunday's post-war election in the mineral-rich Democratic Republic of Congo, but have also raised several security concerns. Some political militants want the vote postponed, pockets of the Congo remain unstable, while many candidates are refusing to campaign. 

Top U.N. officials say despite all the challenges it is surprising there are not more problems, given Congo's immense size, limited infrastructure, and brutal history.

They said this was the biggest election endeavor ever for a U.N. peace mission, costing about $450 million. They said the Congolese and Africa deserve it.

But at a briefing, they also raised the alarm on several security issues.

Mission spokesman Kemal Saiki said there remain pockets of insecurity with active militias and renegade soldiers.

He says everywhere where Congolese can vote without putting their life in danger, they will vote, but in several areas where violence remains high, and they might be killed, it will be difficult for elections to take place.

He says this probably concerns just a small part of the troubled northeastern Ituri region. Disarmament and reintegration of former fighters is ongoing with resistance in several areas even as the election campaign winds down.

But in a troubled country of nearly 60 million people, U.N. officials said they were pleasantly encouraged by the nearly 25 million who have registered to vote.

They also said the capital, Kinshasa, should not be viewed as representative of the entire country, after anti-vote militants went on a rampage there Tuesday.

Fernando Castanon from the mission's human rights division said protests would not be allowed to take place after the campaign ends, even though opponents are planning sit-ins on voting day.

He also expressed concern that the presidential guard intervened during Tuesday's protest, superseding the role of newly trained police. 

U.N. officials have been trying to make sure soldiers and presidential security units remain inside their barracks during the election process, but said these efforts are ongoing.

Deputy Special Representative Ross Mountain explained the role of a new European Union rapid reaction force, known as EUFOR, bolstering the more than 17,000 U.N. peacekeepers.

"Eufor, in fact, was invited. It was an initiative of the United Nations to ask the European Union to send Eufor here," said Mountain. "We see Eufor as part of an insurance policy if you will. We very much welcome it in those terms. We would hope that there will be no need for the insurance policy but most of our troops are indeed in the east of the country. This is extremely welcome."

Political militants opposed to the vote have expressed concern European forces are in Congo to make sure interim President Joseph Kabila, who replaced his assassinated father in 2001, stays in power. They also say it was ill-advised to let him stay in power during the electoral process.

Despite these doubts, Mountain said Eufor was working closely with U.N. forces, and he reiterated his mission's neutrality.

He also said the legislative election would be very important and would lead to a government headed by a prime minister, which he said would not allow a dictatorial president, under a new constitution approved last December.

In the presidential race, Mr. Kabila faces two former rebel leaders, who are currently vice presidents, and 30 other candidates, many of whom have refused to campaign, complaining the voting process is not free and fair.