The incumbent President Joseph Kabila is coming up against 10 rivals while more than 18,500 candidates compete for 500 seats in parliament - will test the central African nation's progress towards stability after decades of misrule and two wars in the last 15 years.

It is the second poll since the end of wars which left four million dead.

At least three people were killed on Saturday in election clashes, leading to a police ban on final campaign rallies in this mineral-rich country, which is two-thirds the size of Western Europe.

Ahead of the vote, international organisations appealed for calm.

Some 22,000 UN peacekeepers are stationed around the country and are expected to help prevent any outbreaks of violence.

Election commission chief Daniel Ngoy Mulunda said on Sunday the country would prove critics wrong by holding credible and peaceful elections.

"Everyone's going to vote tomorrow, it's going to be a celebration of democracy. The Congolese people are going to take the second step in the consolidation of their democracy. We have kept our promise," he said on the eve of the vote.

The first post-war election in 2006 was seen as broadly free and fair but gun battles erupted after the voting.

Doubts over the election have stemmed from delays throughout the process, which meant that preparations for the poll have been last-minute and, at times, chaotic.

United Nations troops and helicopters from Angola and South Africa have been called on to ferry election material to 60,000 polling stations across a nation the size of Western Europe with little infrastructure so some 32 million people can vote.
Provisional results are due on December 6.

However, even in the capital voters complained of last-minute confusion over where they were meant to be voting due to polling stations being moved and errors with voter lists.

The opposition has also protested that election lists were not properly vetted, leading to potential fraud. After outbursts of violence during the campaign, there are also fears of a contested result.