If convicted, he would be barred from running in next year's presidential elections. Sonko and his supporters maintain his legal troubles are part of an effort by President Macky Sall's government to derail his candidacy.

The clashes came a day after police stopped Sonko's "freedom caravan," travelling from his hometown of Ziguinchor, in the south and where he is the mayor, to the capital, Dakar, where he was forced into a home he has in the city.

The interior minister, Antoine Felix Diome, said Sonko had not been arrested but was caught breaking the law -- partaking in an unauthorized caravan -- and taken home.

Sonko supporters were denied access to his house on Monday and threw stones against police blockading the roads. At least eight vehicles were burned with pockets of clashes throughout the city.

Demonstrations have already turned violent in the lead-up to the trial. Last week one person was killed and others injured when clashes erupted between police and Sonko supporters in the city of Kolda in the south. Senegal's government says it will stand firm against any attempt to disrupt public order.