A Senegalese opposition collective on Saturday called for fresh protests starting Monday, following days of clashes that have left at least four people dead.

At a news conference in the capital Dakar, the Movement for the Defence of Democracy -- which includes the leading opposition party Pastef -- urged Senegalese people to "massively descend on the streets".

Police arrested Pastef leader Ousmane Sonko on Wednesday after scuffles with his supporters broke out while he was on his way to court to answer a rape charge that he says is politically motivated.

The arrest sparked violent clashes between opposition supporters and police which continued through Friday, with protesters torching cars and shops in the worst unrest the West African country has seen in years.

Tensions appeared to have eased by Saturday, although looters continued to pillage shops in Dakar.

As well as calling for renewed protests from Monday, the opposition movement demanded that the government release "political prisoners held illegally and arbitrarily".

It also called on the government to respect the right to protest, and demanded it restore the licences of two television channels that were temporarily suspended for broadcasting images of the unrest.

On Saturday, the 15-nation Economic Community of West African States, which includes Senegal, urged all parties in the country to exercise restraint and remain calm.

ECOWAS also called on the government "to take the necessary measures to ease tensions and guarantee the freedom to demonstrate peacefully".

Sonko is due to appear before a judge in Dakar on Monday to face questions about the rape charge.

Senegal has seen days of clashes between opposition supporters and police in the West African state with protesters torching cars and shops in the capital Dakar  
Senegal has seen days of clashes between opposition supporters and police in the West African state with protesters torching cars and shops in the capital Dakar   AFP / JOHN WESSELS

Popular with young Senegalese voters, 46-year-old Sonko has capitalised on frustrations over stubborn poverty and the government's handling of Covid-19.

He ran against President Macky Sall in 2019, but finished third in a race that delivered the incumbent a second term.

Sonko is seen as a potential challenger to Sall in 2024 -- but his political future came into doubt in February after an employee at a beauty salon where he received massages filed rape charges against him.

Frequently critical of Senegal's governing elite, Sonko has accused Sall of conspiring to sideline him from politics.

The 59-year-old president, in turn, has dismissed the allegation that he engineered Sonko's legal troubles.

But to opposition supporters, Sonko's arrest falls into a pattern of court cases against Sall's opponents.

Karim Wade, son of former Senegalese president Abdoulaye Wade, was prevented from running in the 2019 election after being convicted for graft.

Ex-Dakar Mayor Khalifa Sall -- another rival of President Sall's -- was likewise stopped from running in 2019 after being jailed in 2017 for corruption.

The rape allegation against Sonko also comes as uncertainty grows over whether Sall will seek a third term in 2024.

Cheikh Tidiane Dieye, one of the leaders of the Movement for the Defence of Democracy, described Sall at Saturday's press conference as "an apprentice dictator".

Senegalese presidents are limited to two consecutive terms, but Sall launched a constitutional review in 2016, raising suspicions that he intends to run again.

Other presidents in West Africa -- such as Guinea's Alpha Conde or Ivory Coast's Alassane Ouattara -- have used constitutional changes to win third terms.

Senegal, a former French colony of 16 million people, is often heralded as a beacon of stability in an otherwise volatile part of the world.