Police on Tuesday used tear gas and water cannon to break up a protest by hundreds of people in Cameroon's economic capital Douala calling for an end to bloodshed in the country's anglophone regions.

Several parties, including that of opposition leader Maurice Kamto, had called for "peaceful marches" against President Paul Biya, 87, who has ruled the central African country with an iron fist for nearly 40 years.

The marchers called for a ceasefire and negotiations to end a long-running conflict between anglophone separatists and security forces that has claimed more than 3,000 lives.

The protesters also sought a reform to the electoral system.

They converged at a major intersection in a working-class district of Douala, shouting slogans such as "Enough Is Enough" and "Paul Biya Must Go" before police dispersed them, making some arrests.

The police and soldiers had taken up positions in several cities the night before.

On August 24, Kamto, head of the Movement for the Rebirth of Cameroon (MRC) and runner-up to Biya in a 2018 election, labelled his government a "kleptocracy".

He accused Biya of "ruling through disdain and terror" and urged a "giant campaign calling for the pure and simple departure of Mr Paul Biya from power".

Biya on September 7 called regional el ections for December 6 -- prompting the call for Tuesday's marches.

Meanwhile in Paris, about 50 Kamto supporters who demonstrated Tuesday outside the Cameroonian embassy were met with tear gas after clashing with France's CRS riot police, an AFP journalist saw.

Protesters waved Cameroonian flags and held posters reading "Chase away the Tyrant" and called for the end of "Francafrique", the term for France's post-colonial meddling in Africa.

Some threw chairs from a nearby restaurant at police, and traffic was blocked as officers repeatedly dispersed the crowd