In the Democratic Republic of Congo, there are increasing concerns about violence in the lead-up to the release of the results of last week's presidential election.

The country's election commission says it will announce the winner of the poll Tuesday. Preliminary results showed the incumbent, Joseph Kabila, gaining more than 50 percent of the vote. His closest rival, veteran opposition leader Etienne Tshisekedi, got about 34 percent.

On Sunday, Congo's bishops held a rare news conference to appeal for calm. The head of the influential Christian conference warned that Congo is, in his words, like a “high-speed train heading directly into a wall.” He called on the country's leaders to “put on the brakes.”

Both the Kabila and Tshisekedi camps say they are confident of victory and are warning of a renewed outbreak of violence if the vote does not go the way they are predicting.

Last week's balloting was only the second free election since the African nation was torn apart by several years of warfare that ended in 2003.

Already, Human Rights Watch has reported the killings of at least 18 civilians and the wounding of 100 others in election-related attacks.

The voting over three days was described as chaotic, marred by what the U.N. Security Council called “logistical and technical difficulties.”

International observers describe ballots being burned and dumped into mud, especially at voting centers in Kinshasa, the capital, where Tshisekedi has strong support.