Senegal's main opposition leader called on Monday for "much larger" protests, but urged non-violence after days of deadly clashes in the West African state sparked by his recent arrest.

President Macky Sall also called for calm, appealing in an address to the nation for protesters to avoid confrontation.

Opposition leader Ousmane Sonko was freed from detention on Monday, but also charged with rape, while protesters hurled rocks at riot police in the capital Dakar.

Usually considered a beacon of stability in a volatile region, Senegal has been rocked by its worst unrest in years, which began after Sonko was arrested last week.

The arrest of Senegal opposition leader Ousmane Sonko has sparked deadly clashes
The arrest of Senegal opposition leader Ousmane Sonko has sparked deadly clashes AFP / Seyllou

At least five people have been killed in clashes between security forces and opposition supporters, who allege that the rape charge is designed to smear Sonko.

Speaking in Dakar after his release, the opposition leader said "the revolution has already started and nobody can stop it".

He also urged Senegalese people to keep demonstrating, adding that protests should be "much larger", but also peaceful.

Considered a challenger to the incumbent president, Sonko is a government critic popular with young Senegalese. He too denounces the charge against him as politically motivated.

As hundreds of supporters chanted "President! President!" Sonko said Sall did not have the legitimate right to lead the country.

But he opposed any move to remove him from office by force, looking instead towards the 2024 presidential election.

In a nationwide address on Monday evening, Sall appealed to protesters to "silence our bitterness and avoid the logic of confrontation which leads to the worst".

The courts should be left to do their job "in all independence", he added, also announcing an easing of the curfews in place in two regions, including Dakar.

Thousands of Sonko's supporters gathered in a central square in Dakar earlier Monday after he was charged, throwing stones at police and torching a car, before security forces dispersed them with tear gas.

"We cannot allow Macky Sall to flout democracy and imprison his opponents," said Rama Diop, a 30-year-old protester.

On Monday, military vehicles topped with machine guns were stationed in areas of Senegal's seaside capital where there had recently been clashes.

The show of force came after an opposition collective known as the Movement for Defence of Democracy over the weekend called for three days of massive demonstrations.

The unrest in Senegal began last Wednesday after police arrested Sonko on charges of public disorder following scuffles with his supporters.

The 46-year-old opposition leader had been making his way to court for the rape case, accompanied by supporters.

But the move sparked a violent backlash, with protesters looting shops and throwing stones at police, highlighting longstanding grievances over living standards and inequality.

The clashes had abated by Saturday but calls from the opposition to take to the streets fed concerns the violence could escalate.

Schools in the capital have been ordered closed for a week.

Senegal's neighbours and the United Nations have expressed concerns about political tensions in the country and urged calm.

Religious leaders in the majority-Muslim nation of 16 million people also called for peace over the weekend.

Sonko's legal troubles emerged in February when an employee at a beauty salon where he received massages filed a rape accusation against him.

The opposition leader accused Sall of engineering the complaint in order to sideline him from politics. Sall denies the claim.

The rape charge nonetheless comes amid uncertainty over whether the 59-year-old president will seek a third term.

Senegalese presidents are limited to two consecutive terms, but some fear Sall will seek to exploit constitutional changes approved in a 2016 referendum to run again.

To Senegal's opposition, Sonko's case also fits into a perceived pattern of court cases targeting Sall opponents.

The Sonko affair has drawn analogies with Karim Wade, the son of former president Abdoulaye Wade, who was prevented from running in the 2019 election after being convicted for graft.