The main opposition party in the Democratic Republic of Congo says it rejects early election results that give incumbent President Joseph Kabila some 50 percent of the vote.
Opposition candidate Etienne Tshisekedi is estimated to have about 34 percent of the vote so far.
In a show of unity, the 10 opposition parties on Saturday jointly accused Mr. Kabila of irregularities and asked for him to step aside.
The opposition called on African leaders to intervene and avoid a situation like Kenya, Zimbabwe or the Ivory Coast, countries where rulers used the army to cling to power after losing at the polls.
Outside at least one vote-counting center in the capital, Kinshasa, reports Saturday said bags of ballots have split open or been dumped out and are being trampled into the ground.
The election commission has said it will publish full provisional results by December 6th, when Mr. Kabila's term expires.
Monday's election, planned to last only one day, was continued through Tuesday and Wednesday because ballots and voter lists failed to arrive at some polling stations on time.
On Friday, Human Rights Watch said election-related violence killed at least 18 civilians and seriously wounded 100 others.
The U.N. Security Council condemned the violence and expressed concern about what it called "logistical and technical difficulties" during the vote.
A preliminary European Union report says election observers saw ballot box stuffing and ballot shortages, and that some people were turned away from the polls.
African Union and other African observers have said the election was successful despite logistical problems.
Congo's government has said it is bracing for possible violence following next week's announcement of the results.
Some information for this report was provided by AP and Reuters.