Dakar - Plumes of smoke and tear gas spilled into the Dakar sky Thursday as police clashed with opposition protesters. It marked the third day of unrest in Senegal's capital where opposition leader Ousmane Sonko is facing trial for alleged defamation.

Hundreds of protesters surrounded the car taking Sonko to the courthouse as police in riot gear encircled the area.

Just before the officers dispersed the crowd with tear gas, Sonko stepped out of the vehicle to send a message.

"It's the police that are preventing me from moving. It's the police that have prevented me from getting to my hearing," he said. "This is Senegal. The face of Senegal is the dictatorship of Macky, with police repression." He was referring to President Macky Sall.

Protesters gather around the car carrying Ousmane Sonko to the courthouse in Dakar, Senegal, March 16, 2023.

A police spokesperson was not immediately available to comment on the allegation.

Sall's refusal to state whether he'll run for an unconstitutional third term in next year's elections has incensed many Senegalese.

His administration has also been widely accused of silencing dissent through arbitrary arrests.

Senegal's government denies persecuting the opposition or moving away from democracy.

Senegalese opposition leader Ousmane Sonko greets his supporters as he arrives to attend the protest to demand the release of alleged political prisoners ahead of his court appearance on Thursday on libel charges, in Dakar, March 14, 2023.

Sonko is facing libel charges for allegedly accusing tourism minister Mame Mbaye Niang of embezzlement.

Sonko also faces separate charges for rape, which his supporters say were fabricated to prevent him from running for the presidency. Sonko has denied all allegations.

His arrest a year ago ignited a week of rioting that led to the deaths of 14 people.

No deaths have been reported in this latest round of protests, but violence on Thursday was widespread. Demonstrators hurled rocks at police, burned down grocery stores and destroyed bus depots. They hauled parked cars onto streets to act as roadblocks, and smashed windows.

Supporters of Senegal opposition leader Ousmane Sonko clash with security forces ahead of their leader's court appearance for a libel case against him in Dakar, Senegal, March 16, 2023.

Paulin Maurice Toupane is a senior researcher at the Institute for Security Studies in Dakar.

Senegal, he said, is at a tipping point.

"Senegal must do everything it can to avoid reaching the level of instability we see in other countries in the region," Toupane said.

West Africa has suffered a series of coups in the last few years, and instability in Senegal - long considered the region's most solid democracy - could ripple beyond its borders.

Tensions are only expected to grow as the country gets closer to the presidential election in February 2024.

Protesters run from tear gas in Dakar, Senegal, March 16, 2023.

Sonko came in third in the 2019 presidential election and has since grown in popularity, mainly among Senegalese youth.

Twenty-six-year-old Mouhamad Diakho was among the protesters.

"I'm very sad about this situation in our country. I'm so sad," said protester Mouhamad Diakho, 26. "I'm not happy about what is happening. I got this shame inside of me. I got this anger inside of me. Because we the Senegalese people don't deserve this. We deserve peace. We deserve love."

A rally for Sonko on Tuesday drew an estimated 10,000 supporters.