Maldives leader Ibrahim Mohamed Solih was trailing in Saturday's presidential vote, preliminary results showed, triggering a runoff election due later this month.

Solih's attempt for a second term has turned the poll into a referendum on his pursuit of renewed ties with India, the archipelago nation's traditional benefactor.

Preliminary results showed Solih in second place with 39.1 percent of the vote with his main challenger, the Mayor of Male Mohamed Muizzu, leading with 46.08.

Nearing midnight on Saturday, and with less than 20,000 more votes left to be counted, it was clear that neither of the candidates could reach the absolute majority needed for an outright victory.

The Elections Commission has set September 30 as the date for a runoff between the first two candidates. The official declaration of the results are expected on Sunday.

Some 282,000 Maldivians over 18 years were eligible to vote. Election officials said the final turnout was projected at about 75 percent, compared to nearly 90 percent at the 2018 poll.

Previous votes have been marred by violent clashes as well as allegations of widespread voting fraud, but there were no immediate reports of any violence or rigging.

Police said they detained two people in connection with election-related incidents, but did not give further details.

"There have been no significant reports of unrest anywhere," Solih told reporters after casting his ballot.

"The election campaign activities had also proceeded very smoothly. There is unprecedented peace in the Maldives."

Former president Maumoon Abdul Gayoom, whose son is an opposition candidate, voted early and wished the nation well.

"May Maldives continue to reap the benefits of true democracy and peace in the years ahead," Gayoom said on X, formerly known as Twitter.

- Party split -

Solih, who was dressed in a yellow T-shirt and cap, the colours of his Maldivian Democratic Party (MDP), addressed a large gathering in the capital Male on Friday.

His main rival, 45-year-old Muizzu, a proxy of jailed opposition leader and former president Abdulla Yameen, attended a mass rally marking the end of a short campaign.

Convicted prisoners in the Maldives can vote but Yameen did not register to vote at his Maafushi high security prison, officials said.

Yameen is serving an 11-year sentence following his corruption conviction in December.

Eight candidates are contesting for the top job in the nation of 1,192 coral islets, scattered in a long line stretching around 800 kilometres (500 miles) across the Indian Ocean.

Solih polled 58.3 percent at the previous election in 2018, but this time his Maldivian Democratic Party (MDP) has split, with another candidate in the running.

MDP's breakaway candidate Ilyas Labeeb was a distant third with 6.91 percent. 

After his shock victory five years ago, Solih moved swiftly to repair relations with New Delhi strained under Yameen, who banked on Beijing for loans and diplomatic support.

During his autocratic five-year tenure, Yameen borrowed heavily from China for construction projects, making the nation -- better known for upscale beach tourism and celebrity travellers -- a hotbed of geopolitical rivalry.

Balloting also took place in overseas locations with large Maldivian populations, such as Trivandrum in the southern Indian state of Kerala, as well as in the capitals of Malaysia, Sri Lanka, Britain and the United Arab Emirates.

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