Kenyan police fired in the air to disperse hundreds of opposition supporters outside the airport in Nairobi, a Reuters witness said.
Despite a partial ban on protests in the capital, demonstrators gathered near the airport to wait for the return of their leader, Raila Odinga, from an overseas trip.
Demonstrators threw rocks at police trying to disperse them, the witness said. Police were checking vehicles headed from the city centre to the airport in another attempt to stop the demonstration from building.
Odinga has called for a “National Resistance Movement” to protest the outcome of the repeat election, ordered by the Supreme Court after it annulled the results of an August poll over procedural irregularities.
President Uhuru Kenyatta won a second, five-year term with 98 % of the vote after Odinga boycotted the contest. Only 39% of registered voters took part.
The court will rule on Monday on cases seeking to nullify last month’s repeat vote. Judges could order a fresh vote or clear the way for the incumbent to be sworn in for another term.