Senegal's President Macky Sall asked the government on Wednesday to take measures to "preserve public order" after protests over the trial of opposition leader Ousmane Sonko left at least one person dead.
Violence has flared in several cities since Sonko's defamation trial opened on March 16, a case that could make him ineligible to contest next year's presidential elections.
A man was killed on Tuesday during clashes between Sonko's supporters and police, according to local officials.
Sall said the government should "take all appropriate measures to ensure the absolute security of goods and people", according to an official statement.
Sonko is being tried for allegedly defaming Tourism Minister Mame Mbaye Niang, a member of President Sall's party.
The opposition leader has been receiving medical treatment since he was allegedly sprayed with tear gas and manhandled last week as authorities escorted him to a courthouse.
A hearing in Sonko's trial has been postponed to March 30.