Thousands of protesters took to the streets of Haiti's capital as tensions grew over the result of last week's vote.
Roadblocks were set up and tyres set alight in Port-au-Prince as protesters clashed with UN peacekeepers.
Supporters of Rene Preval, the presidential front-runner, claim officials are tampering with the vote to stop him winning.
At least one person was killed and several injured in clashes, with UN forces denying claims they fired into a crowd.
Thousands of chanting protesters forced their way into the Hotel Montana, used by electoral officials tallying the vote.
Prevented from reaching the officials, the demonstrators - many from Haiti's slums - frolicked in the hotel pool.
Archbishop Desmond Tutu, among the hotel guests, appealed to the crowds for calm but did not leave.
Last week's elections were largely peaceful but the threat of violence hangs over a possible run-off vote on 19 March.