Joseph Kabila, the incumbent president of the Democratic Republic of Congo (DRC), has been declared the provisional winner of the country's presidential poll.
The provisional results were announced on Friday by the DRC election commission after several days of unplanned delays.
Kabila won 49 per cent of the 18 million ballots cast, with veteran opposition leader Etienne Tshisekedi winning 32 per cent, election commission chief Daniel Ngoy Mulunda said. Voter turnout was 59 per cent, he said.
In a statement sent to the AFP news agency, Tshisekedi rejected the election result and proclaimed himself the rightful president of the country.
"I consider this [result] declaration a outright provocation to our people and I reject it in full. As a result, I consider myself from this day on as the elected president of the Democratic Republic of Congo," the statement read.
He called on the international community to "find a solution to this problem [and to] take all possible measures so that the blood of the Congolese people is not spilled again".
To his supporters, whom he calls "fighters", he said: "I urge you to stick together as one man behind me to face the events that will follow."
Plumes of black smoke were visible over the city after the decision was announced, as opposition supporters burned tyres in parts of the capital.
Gunshots rang out in the eastern neighbourhood of Limite and in the central area of Bandale, where protesters also threw stones at a heavy contingent of armed police, who fired tear gas to disperse them.
Lambert Mende, the communications minister, said that Tshisekedi's declaration that he was president was "nonsense and illogical", and warned that it could cause violence.
"We're calling for Mr Tshisekedi to come back to legality and not to threaten the peace of the country just because the people didn't choose him," he told the Reuters news agency.
In the tightly controlled pro-Kabila downtown neighbourhood in Kinshasa, near the election commission, people hung out of balconies cheering after the results were released.
Police in riot gear in trucks stood at attention.
In the Limite neighbourhood, where the 78-year-old Tshisekedi lives, the mood was dark.
"This is a total disaster," said Fabien Bukasa, a Tshisekedi supporter. "We are thinking about what to do. We do not know what will happen."
The results are in line with preliminary results which had indicated that Kabila held an unassailable lead, Al Jazeera's Yvonne Ndege reported from Kinshasa, the country's capital.
The opposition had earlier rejected those partial results, and threatened "serious unrest" across the country if Kabila was declared the winner, our reporter said.
The election commission has said the repeated delays to a final announcement of the results were due to double-checking of figures against tally sheets from polling stations to avoid mistakes.
An international observer, speaking to Reuters on condition of anonymity, said that a number of irregularities had, however, already shown up in the results released by the commission.
In some districts of the Katanga province, for example, voter turnout was recorded as being near 100 per cent, with almost all of the votes going to Kabila.
"These demonstrate a pretty massive level of voter fraud simply because that level of turnout is impossible. It is impossible for 100 per cent of votes to go to one candidate," the observer said.
Kabila, in power since 2001, will now serve out another five-year term if the results are ratified by the country's apex court. He was expected to hold on to his position, having run against a divided opposition field of 10 candidates in the single-round race.
The country's Supreme Court will hear election disputes and declare a definitive winner on December 17. Judges at the country's apex court are, however, seen as being close to Kabila. The president expanded the court's bench from seven to 27 at the start of the campaign.
Although international observers said the November 28 vote was flawed, most have stopped short of calling it fraudulent, saying the irregularities were not widespread enough to have caused a change in outcome.
The conflict-prone country has been on edge since the polls which were preceded by deadly clashes between police and opposition supporters in Kinshasa.
Police have been out in force in the capital and about 20,000 soldiers are on stand-by at military bases with security forces seemingly determined to quash any opposition demonstrations before they could start.
Speaking to Al Jazeera, Nshole Babula, the secretary-general of Union of Bishops of Congo, said he was worried about the prospect of violence: "We are worried about what might happen when results are released because the opposition says they will protest and we are concerned to see so much of police presence in the city.
"This is why the Catholic church has asked those who have a problem with the results to address their complaints through the legal route."
Speaking about allegations of fraud, Babula said: "It is difficult to say there is fraud, but we say that CENI [the election commission] must be transparent … the manner in which they are publishing results, it is not possible to verify results."