At least four protesters were killed during clashes with security forces in Cameroon on Sunday as opposition supporters rallied to demand credible results from the recent presidential election, a local governor said.

Hundreds stormed the streets in different cities following days of unrest and in response to protest calls by opposition candidate Issa Tchiroma Bakary, who claims to have defeated President Paul Biya in the Oct. 12 election.

The African Movement for New Independence and Democracy opposition party and local media earlier reported that at least two protesters were shot dead by security forces as they sought to disperse the protests.

Dozens of opposition supporters, activists and leaders have already been arrested in recent days as protests continued.

Cameroon’s Minister of Territorial Administration Paul Atanga Nji told reporters Saturday that the government arrested several people plotting violent attacks.

Tensions were building up ahead of the election in Cameroon, a country of nearly 30 million people.

The decision by the 92-year-old Biya, the world’s oldest leader who has been in power for nearly half his life, to seek reelection angered the country's youth and the opposition.

The opposition has accused Biya of having a hand in the disqualification of his strongest rival and of using state machinery to manipulate the election in his favor.