Felix Tshisekedi of Congo's Union for Democracy and Social Progress opposition party, at a press conference in Nairobi, Kenya. Congo's Constitutional Court early Sunday, Jan. 20, 2019, declared the election of Tshisekedi as president. File picture: AP Photo/Ben Curtis.

DR Congo was on Monday making plans to install Felix Tshisekedi as its new president this week after a long and bitter election whose outcome was disputed by the runner-up and shunned by many western nations. 

The ceremony, which was scheduled for Tuesday but looks increasingly likely to happen on Thursday, will see the 55-year-old sworn in as president, replacing Joseph Kabila who has ruled DR Congo since 2001.

The inauguration looks set to draw a line under three weeks of growing tension over the long and drawn-out counting process after the December 30 vote, which provisionally declared Tshisekedi, one of two opposition candidates, the winner. 

But the outcome was swiftly denounced by his opposition rival Martin Fayulu, who filed an appeal. He claimed he had been cheated of an outright victory by an "electoral coup" masterminded by Kabila with Tshisekedi's approval.

Although leaked figures from the provisional count appear to be heavily in his favour, the Constitutional Court dismissed his appeal.

At stake is political stewardship of the mineral-rich but notoriously unstable central African nation.

Democratic Republic of Congo has a population of some 80 million and covers an area the size of western Europe. 

- Clashes in Kinshasa -
With officials due to meet to pin down the specifics of the ceremony, tension was building in the capital. Some 300 Fayulu activists clashed there with motorbike taxi drivers whom they took for Tshisekedi supporters, leaving one driver nursing a serious head injury, an AFP correspondent said.

Several journalists were also hurt in the fracas. The Actualite news website said one of its reporters was "assaulted by police" while others were attacked by Fayulu supporters who accused them of being pro-Tshisekedi.

With the swearing in due to happen this week, officials had yet to confirm the date of the ceremony.

"According to information I had this morning, the (ceremony) has been delayed until Thursday," said a spokeswoman for Cach, the opposition coalition which backed Tshisekedi.

And Jean-Pierre Kambila, a senior figure in Kabila's outgoing cabinet, said the date would be settled during talks later in the day.

"If this ceremony doesn't take place tomorrow, it will be on January 24, without a doubt," he said. 

- 'Don't encourage fraud' -

Without a firm date, officials have so far been unable to send out invitations to foreign heads of state and government -- and given the very public dispute over the result, it remains to be seen who will actually turn up. 

The court's dismissal of Fayulu's appeal and its subsequent confirmation of Tshisekedi as the president-elect has divided sub-Saharan Africa.

The 16-nation Southern African Development Community congratulated Tshisekedi, as did Kenya, calling for a peaceful transition of power.

But the result reignited longstanding divisions among the nine nations bordering DR Congo.

Burundi and Tanzania, who are working with Kinshasa to fight rebels on their common border, sent congratulations, while Republic of Congo, Uganda, Rwanda, Zambia and Angola remained silent.

Fayulu, who has declared himself "president-elect", has urged the international community not to formally recognise Tshisekedi.

"I urge the African presidents who asked the Congolese people to respect the Constitutional Court's decision, to respect the sovereign decision of the Congolese people who elected me president with more than 60 percent of the vote," he wrote on Twitter. 

"We should not encourage fraud, lies and falsehood," he said.

- AU, EU unconvinced -

For Rwanda, the court's swift decision has been a slap in the face for President Paul Kagame, currently the AU chairman.

The AU had expressed "serious doubts" about the provisional outcome, and urged the court to delay its announcement pending a visit by Kagame and AU Commission president Moussa Faki on Monday. 

But the weekend announcement caught the AU off guard, sweeping aside its concerns and prompting it to "postpone" the visit.

The European Union had also expressed reservations, saying "doubts remain regarding the conformity of the result".

DR Congo's influential Roman Catholic Church has also dismissed the outcome, saying it "does not correspond" with data collected from polling stations by its 40,000 election monitors.

On paper, at least, DR Congo appears to be going through its first-ever peaceful handover of power since independence from Belgium in 1960.

The president elect is the son of DR Congo's Etienne Tshisekedi, a veteran politician who founded the country's oldest and largest opposition party. 

Although he has won the prize that eluded his father for 35 years, the portly 55-year-old has never held high office.

In recent decades, DR Congo has lived through two regional wars (1996-97 and 1998-2003) with the last two presidential elections, in 2006 and 2011, marred by bloody clashes.