The main opponent of Guinea's head of state in the country's recent presidential election on Sunday called for a general strike Monday in the capital Conakry after Alpha Conde was declared the winner.
It was a question of "protesting against the electoral 'hold-up' and of demanding respect for the truth of the ballot boxes", Cellou Dalein Diallo said in a video posted on social media.
The Constitutional Court on Saturday declared Conde winner of a controversial third term as president while Diallo called for resistance "by all legal means".
With 59.5 percent of the votes cast, Conde's support surpassed the absolute majority needed to win in the first round, judges found, throwing out challenges to the October 18 ballot from figures including Diallo.
The official count from the Ceni national election commission gave Diallo 33.5 percent.
But the 68-year-old insists that data his activists gathered at polling stations shows he won the vote and is the victim of fraud.
While observers from other African countries have backed the official results, France, the European Union and United States have cast doubt on them.
Even before the election, the incumbent's announcement that he would stand again triggered months of demonstrations and violence claiming dozens of lives, almost all of them civilians.
There is no way for Conde's opponents to appeal the constitutional court decision, leaving the path clear for the president to begin a new six-year term -- with the option for a second under a new constitution introduced in March.
A former opposition leader who suffered imprisonment and was even sentenced to death, Conde became Guinea's first democratically-elected leader in 2010 and won re-election in 2015, but he has been accused of drifting into authoritarianism.
Diallo, a former prime minister, has unsuccessfully challenged Conde in each election the president has contested.