Senegal opposition leaders say they received last-minute government authorization to hold a demonstration against the aging president's bid for re-election.
The government previously said it would not authorize Monday's rally, setting up a potential clash because the opposition said it would demonstrate anyway.
Alioune Tine, one of the leaders of a coalition of groups calling for the departure of President Abdoulaye Wade, said Wade himself intervened to authorize the afternoon rally.
The U.S. Embassy has warned of unrest leading up to Friday's announcement by the constitutional council which is expected to validate Wade's candidacy in the February election. Wade is hoping to run for a third term, even though the constitution was revised to only allow two.