Sonko is being sued for defamation and public insults, charges stemming from accusations he made against Senegal's tourism minister at a news conference late last year. On Thursday, the trial was postponed until next month.
After leaving the courthouse, Sonko greeted his supporters from his car. Police soon began firing tear gas at the gathering.
SENEGAL BUS CRASH CLAIMS LIVES OF 40, DOZENS OTHERS INJURED: REPORTS
The police in Senegal smashed the car of an opposition leader and forcibly removed him from the vehicle. (Fox News)
"The convoy of the main opposition leader is blocked by combat vehicles," said Sonko's lawyer, Cire Cledor Ly, in a text message to AP on Thursday afternoon. It's unclear why the car was stopped and the government did not immediately respond to requests for comment.
Sonko rose to prominence during the 2019 presidential election and is regarded as the frontrunner to challenge President Macky Sall in next year's elections.
The trial comes while Sonko is battling charges of rape, where if convicted, he faces up to 10 years in jail and would be barred from running for president. Sonko's supporters say the government is trying to derail the opposition leader's political future.
Rallies to support Sonko have previously turned violent.
Two years ago, at least 13 people were killed as supporters clashed with police after Sonko was arrested for disturbing public order while on his way to the courthouse for a scheduled appearance on the rape charges.