The outcome of DR Congo's tempestuous presidential election appeared to be headed for the courts Friday after the poll's runner-up said he would demand a recount.
Martin Fayulu, an opposition candidate tipped by pollsters as the likely winner of the December 30 vote, told supporters: "We will go to the Constitutional Court on Saturday... (to demand) a recount of the vote."
He said he would ask election chief Corneille Nangaa "to produce the tally reports from polling stations in front of witnesses" and Congolese and international observers.
Provisional results released on Thursday declared Felix Tshisekedi, a rival opposition candidate, the victor with 38.57 percent of the vote, just ahead of Fayulu with 34.8 percent. 
Emmanuel Ramazani Shadary, the candidate backed by outgoing President Joseph Kabila, came a distant third with 23.8 percent. Turnout on the day stood at 48 percent.
The declared result was a surprise to many.
The few pre-election opinion polls had flagged Fayulu as the clear favourite while Kabila critics predicted the outcome would be rigged in favour of Shadary rather than an opposition figure.
The powerful Roman Catholic church on Thursday bluntly said the result "does not correspondent" with data that its 40,000 election monitors had collected at polling stations. 
Fayulu's bloc on Friday said he was the true victor, claiming he had garnered 61 percent of the vote.
Candidates have 48 hours after the result to file any appeal, and the Constitutional Court has a week in which to deliberate.
"We don't expect the election to be annulled, but (a decision in favour of) a recount," Fayulu said.
Democratic Republic of Congo has been in the grip of a two-year political crisis triggered by Kabila's refusal to step down when his two-term constitutional limit expired at the end of 2016.
Elections to choose a successor were delayed three times before finally taking place on December 30.
Polling day unfolded relatively peacefully, but suspicions over the count have deepened.
The turmoil has darkened hopes that the country will have its first peaceful handover of power since it gained independence in 1960.
DRC is a giant, straddling central Africa over an area the size of continental western Europe.
Rich in minerals but mired in poverty, the country has suffered two major wars in the past 22 years, as well as bloodshed in elections in 2006 and 2011 that saw Kabila returned to office.
International reactions to the results have been guarded.
Most leaders have issued statements appealing for any disputes to be resolved peacefully, but notably lacking any congratulations for Tshisekedi. 
With the UN Security Council expected to discuss the situation later on Friday, Congo's election chief appealed to the body to support the new leadership. 
"Now it is time, with the beginning of this mandate, for the new authorities to be supported by the international community," Nangaa said.
Analysts said it was likely Kabila, 47, had sought to avoid a backlash and international condemnation if Shadary had been declared winner.
He therefore struck a deal with Tshisekedi, head of the country's oldest and biggest opposition party, according to this scenario.
As a quid pro quo, some commentators suggested, Kabila would gain immunity from prosecution for his iron-fisted 18-year rule, and protection from asset seizure.
Thursday's pre-dawn announcement brought thousands of Tshisekedi supporters onto the streets in celebration, while others who had backed Fayulu came out to protest.
Five people were killed in the resulting clashes with police. 
Addressing a crowd in Kinshasa, Tshisekedi paid tribute to Kabila whom he described as "a partner for democratic change".
Also Friday, the election commission (CENI) was expected to announce the result of legislative elections which took place on the same day, with more than 15,000 candidates in the running. 
The result will determine who will hold a majority in the 500-seat parliament for the next five years. 
The outgoing National Assembly, which took power in 2011, is currently dominated by Kabila supporters who, even ahead of the announcement, were already claiming to have won a majority.