Cameroon’s main opposition leader, Maurice Kamto, has been barred from contesting in the country’s upcoming presidential election, a decision that has raised concerns of potential unrest and further cemented expectations of another term for long-time incumbent, President Paul Biya.

The country’s electoral commission, ELECAM, unveiled a provisional list of 13 approved candidates at a press conference on Saturday, excluding Kamto, according to a report by Al Jazeera. No official reason was provided for his rejection, although disqualified candidates have 48 hours to appeal.

Kamto, 71, who finished second in the 2018 election with 14% of the vote, had submitted his candidacy just a week earlier. President Biya, in power since 1982, won that election with over 70% amid widespread allegations of electoral fraud and low voter turnout.

This time, Kamto had attempted to run under the banner of the African Movement for New Independence and Democracy (MANIDEM), a left-wing party. He previously ran as the candidate of the Cameroon Renaissance Movement (MRC), which he founded in 2012.

Kamto’s exclusion has sparked anxiety and tension across the country. In Yaoundé, the capital, and Douala, the commercial hub, security forces have been deployed around ELECAM headquarters and key roads amid fears of protests.

The United Nations Department of Safety and Security had earlier issued warnings that the announcement could trigger demonstrations.