Opposition parties in Democratic Republic of Congo have rejected partial results released by the electoral commission giving incumbent President Joseph Kabila an early lead in the vote count from the November 28 presidential election. In a joint statement signed by major parties, including that of veteran opposition leader Etienne Tshisekedi, the opposition on Saturday cited irregularities and said the electoral commission was "psychologically preparing the population for fraud". "As a consequence, we reject these partial results and consider them null and void," the opposition said in a statement. It added that the manner the commission was releasing the results was illegal. The opposition also called for mediation by other African leaders, but rejected forming a government of national unity with Kabila. Al Jazeera's Yvonne Ndege said that all 10 opposition presidential candidates had rejected the partial results.She also said people were questioning why early results where not released from capital Kinshasa, despite 62 million votes being case there. "The opposition says results from Kinshasa are not being released because the capital is a stronghold for the opposition and Kabila would not have won here," she added. While rejecting the results, Tshisekedi, the leader of the opposition Union for Democracy and Social Progress (UDPS), issued a warning to Kabila and the chief of the National Electoral Commission (CENI), Daniel Ngoy Mulunda. Partial results released by CENI on Friday showed Kabila with 52 per cent of valid votes to 34 per cent for Tshisekedi, but the count included more of the incumbent's traditional strongholds than his main rival's. "I'm warning Mr Ngoy Mulunda that the UDPS not only rejects these results, but warns Mr Ngoy Mulunda and Mr Kabila to respect the will of the Congolese people in publishing the results that will follow," he said. "I'm going to say that, if they don't, they risk committing suicidal acts. I call all our people to stay vigilant so that if needed they can execute the orders I will give them," he added. UDPS Secretary General Jacquemain Shabani Lukoo said that the government risked sparking violence over the alleged massive fraud. "If they carry on like this there will be trouble, that's for sure, we will not let this lie," he said. The elections are DR Congo's second since back-to-back wars from 1996 to 2003. Fears of post-poll violence are running high after a campaign marred by deadly police crackdowns on opposition rallies and a series of clashes between Kabila's and Tshisekedi's supporters.