Live bullets have been fired in Kisumu, western Kenya, the BBC’s Emmanuel Igunza reports.
Two people have been wounded – both have had gunshots to the thigh.
One of the injured is a 15-year-old boy and the other is a 21-year-old man.
They are both being treated in hospital.
Relatives at the hospital say police shot the live rounds.
Our correspondent adds that tear gas has also been fired and crowds have dispersed from the main square in the opposition stronghold.
Why is Kenya in this situation?
A Daily Nation article looks out how Kenya got into the situation today, where the opposition are boycotting a re-run of the presidential election.
It goes with the headline “Why last-ditch effort to broker poll deal fell apart”.
It claims that under-the-radar mediation failed.
It adds that a meeting took place last Saturday at a Country Club hosted by business people.
It describes it as “the last in a series of quiet gatherings in the past two weeks involving a cross-section of interest groups, who were all keen to broker a ceasefire and prevent an eruption of ethnic and political violence over the contentious election”.
But ultimately these meetings didn’t succeed, as the Nation reports, “the groups could not agree on a common position” to present to President Uhuru Kenyatta and National Super Alliance leader Raila Odinga.
This photo shows police using water cannon:
