The ex-leader of the Maldives, Mohamed Nasheed, faces a tricky run-off after failing to win a majority in presidential polls he hoped would seal his return to power 18 months after he was toppled.

Nasheed was the clear winner of Saturday's first round but analysts said he would be disappointed in failing to pass the 50 percent threshold and would now face an uphill task to seal his comeback in the second round of voting on September 28.

The Elections Commissionyesterday formally announced the run-off between Nasheed, who secured 45.45 percent of the popular vote on the honeymoon islands, and his nearest rival

Abdullah Yameen, who garnered 25.35 percent.

The two other candidates, both of whom have been fiercely critical of Nasheed, could now prove a major stumbling block to the climate change activist's hopes of storming back to power after his ousting in February 2012.

Nasheed has maintained he was the victim of a

"coup" after a mutiny by the security forces but Saturday's vote passed off without violence.

Nasheed's Maldivian Democratic Party (MDP) said it "preferred" an outright victory on Saturday, but was prepared to face the next round of balloting even as parties scrambled to form new coalitions.

A spokesman for incumbent President Mohamed Waheed, who suffered a humiliating defeat receiving just 5.13 percent of the vote, said he was already planning to back Yameen, half brother of former strongman president Maumoon Abdul Gayoom.

Maldivians came out in force on Saturday, forming long queues outside polling booths under bright sunshine.

Regional power India and UN Secretary General Ban Ki-moon had called for free and fair elections to end a year and a half of political turmoil on the tropical archipelago.

Voting took place on all major inhabited islands as well as at the tourist resorts that have made the country famous as a "paradise" destination.