Police in Senegal clashed with protesters Saturday, in the fourth consecutive day of unrest related to next week's presidential election.

Protesters in the capital, Dakar, threw rocks at police as they called for 85-year-old President Abdoulaye Wade to abandon his bid for a third term in office.

Police responded by firing tear gas at the demonstrators. Interior Minister Ousmane Ngom has defended the government ban on the protests, which he said are “seditious” and “criminal.”

Opposition parties want President Wade to abandon his run for a third term, which they consider illegal. A court ruled the constitution's two-term limit does not apply Mr. Wade because he was in office before it took effect.

That ruling, two weeks ago, sparked riots that have killed four people.

Also Saturday, early voting started for the country's 23,000 security officers.

Candidates challenging the president include his former allies Macky Sall and Idrissa Seck. A run-off will be held if no one wins a majority. Many observers say a run-off is not likely because no opposition frontrunner has emerged.

One candidate, Cheikh Bamba Dieye, was arrested briefly during protests on Friday but was released a short time later.