Hundreds of protesters have clashed with security forces in several cities across Cameroon, a day before the results in a highly-contested presidential election are due to be announced.

Police fired tear gas and water cannons at the supporters of opposition candidate Issa Tchiroma Bakary in his stronghold of Garoua, a city in the north of the country.

The protesters were denouncing what they said was a plan by the ruling party, the Cameroon People's Democratic Movement (CPDM), to 'steal the victory' from the opposition leader.

Tchiroma Bakary has insisted that he won the presidential election held on 12 October, challenging incumbent President Paul Biya's 43-year hold on power. The CPDM party has dismissed the claims.

The demonstrations come after Tchiroma Bakary called on his supporters in the country and the diaspora to march peacefully to 'liberate Cameroon'. Authorities have banned gatherings until Monday, when Cameroon's constitutional council is set to announce the results.

In Garoua, the demonstrations began peacefully but quickly turned rowdy when security forces threw teargas on the streets to disperse the hundreds of people that had gathered in support of Tchiroma Bakary.

'We are not here for disorder. We're demanding the truth of the ballot,' a placard read.

One protester was seen carrying a banner urging US President Donald Trump to help them.

'We are here to claim our victory. We are making a peaceful march, which is a civil right for all Cameroonians - for everyone,' another protester stated.

Supporters also took to the streets in the south-western city of Douala. 'We want Tchiroma, we want Tchiroma,' protesters chanted, Reuters news agency reports.

Tchiroma Bakary previously told BBC that he would not accept a stolen vote. He said his team had compiled the overall picture based on results from individual polling stations.

In a video statement posted on social media, Tchiroma Bakary asserted he had won the election with about 55% of the vote, based on returns representing 80% of the electorate. The 76-year-old former government minister broke ranks with Biya, 92, who is seeking another term after 43 years in power.

The CPDM has dismissed Tchiroma Bakary's victory claims; several officials have characterized it as illegal since only the constitutional council can proclaim official results.

Opposition supporters have alleged that the 12 October poll was marred by irregularities, including ballot-stuffing. Judges on the constitutional council rejected eight petitions as they found insufficient evidence of irregularities.

Tchiroma Bakary chose not to file complaints with the council, which has judges appointed by Biya; instead, he declared himself the 'legal and legitimate president.'

Born in Garoua, Tchiroma Bakary trained as an engineer in France before returning to Cameroon to work for the national railway company. In 1984, he was imprisoned, accused of an attempt to depose President Biya, but he always denied the allegations.

He served as communications minister from 2009 to 2019, staunchly defending Biya's government during crises like the Boko Haram insurgency, but in June, he resigned, announcing his presidential candidacy.