MALE, Maldives (AFP) - The election authorities in the Maldives on Monday rescheduled the twice-aborted presidential vote for Nov 9, two days after the police blocked the last attempt, saying it was illegal.

"Dear all, 1st round of the presidential elections to be held on Nov 9th and 2nd round on Nov 16th," the independent Elections Commission chief Fuwad Thowfeek said on Twitter.

The Maldivian Constitution requires that a president be inaugurated by Nov 11, but Mr Thowfeek did not say what would happen if no candidate gets the required 50 per cent to secure an outright win in the first round.

That would leave the Maldives without a leader for five days until the completion of the second round run-off.

Maldives police on Saturday halted an election that opposition leader Mohamed Nasheed was expected to win.

Police blocked the vote saying it was illegal for the election to go ahead without all three candidates approving the names of all voters as required by the Supreme Court.

Only Mr Nasheed had signed off the electoral lists by Friday evening.

An earlier round won by Mr Nasheed on Sept 7 was annulled by the Supreme Court, which held that there were irregularities, although international observers gave it a clean chit.

Asian and Western diplomats have warned that the Maldives could be heading for a constitutional crisis and a power vacuum if a president is not elected before Nov 11.

The United Nations and the European Union have joined an international chorus opposing the cancellation of the elections on Saturday.

European Union foreign policy chief Catherine Ashton in a statement warned that failure to hold credible elections will damage Male's relations with international partners.

"Further instability would also damage the country's economy and its relations with its international partners," she warned.

Mr Nasheed, who was toppled as Maldives leader 20 months ago, has called on President Mohamed Waheed to step down and let the Speaker of Parliament conduct a fresh presidential vote.

Observers say there should be no surprise at the turmoil as key institutions are still run by followers of the country's long-time dictator Maumoon Abdul Gayoom, who never accepted Mr Nasheed's 2008 victory.