Democratic Republic of Congo's President Joseph Kabila and challenger Jean-Pierre Bemba face a second round run-off after neither won a majority in Congo's July presidential election.
After the results were made public Sunday evening, supporters of the two rivals traded gunfire in Kinshasa. The violence left at least one person dead and six others wounded.
Independent electoral commission chief Apollinaire Malu Mallu announced Mr. Kabila won just under 45 percent of the vote, short of a majority. He said on public television that Bemba came in second with about 20 percent of the vote.
The run-off election is expected to be held October 29.
United Nations Secretary General Kofi Annan late Sunday called the July 30 election an "historic milestone" and urged both candidates to solve their disputes by electoral law.
The third place finisher was veteran politician Antoine Gizenga with 13 percent of the vote.
Turnout among Congo's 25 million voters was 70 percent for the election - the country's first poll in 40 years.
The results remain provisional until they are approved by Congo's supreme court.
Some information for this report was provided by AFP, AP and Reuters.