Haiti President, Michel Martelly, has stepped down at the end of his term amid tension over how he is to be replaced.
No successor has yet been chosen as opposition supporters challenged a deal to select an interim leader.
Under the latest agreement, parliament would elect an interim president and install a transitional government for a four-month term.
The runoff vote to elect his successor was shelved because of fears of violence and allegations of fraud. It will now be held on April 24, with a new president due to be sworn in on May 14.
Mr Martelly is constitutionally barred from seeking re-election, but has thrown his weight behind Jovenel Moise, a banana exporter who won the first round of the presidential election in November.
But the result has been contested by the opposition challenger, Jude Celestin.
He accused the electoral authorities of favouring Mr Moise and threatened to pull out of the runoff vote.
Haiti is still struggling to recover from a huge earthquake in 2010.