The disciples of influential Muslim leader Cheikh Bethio Tioune vandalized cars and boutiques in the Senegalese capital.
An Associated Press reporter saw one bus in flames on one of the main commercial boulevards, as well as two other buses which had been destroyed by rock-hurling supporters.
Tioune counts thousands of followers. He is among a new breed of marabouts who are accused of mixing mysticism with politics. In the run-up to the recent presidential election, local newspapers accused him of accepting money from ex-President Abdoulaye Wade in return for instructing his followers to vote for him.
Wade was defeated at the polls in March and Tioune was arrested on April 23.