Maldives President Abdulla Yameen declared a state of emergency on Wednesday, giving security forces sweeping powers to arrest suspects ahead of a major anti-government protest rally.
The move, announced on Twitter, follows an alleged attempt to assassinate Yameen and the discovery of a bomb near his official residence.
The declaration comes two days before a planned protest by the main opposition Maldivian Democratic Party (MDP), whose leader Mohamed Nasheed is in jail after a widely criticized conviction under anti-terror laws.
“President Yameen has declared state of emergency to ensure the safety and security of every citizen,” his spokesman Muaz Ali tweeted.
Official sources said the declaration of the state of emergency, initially for a period of 30 days, would lead to the automatic suspension of several constitutional provisions including the right of association.
Tensions are high in the honeymoon island nation following an explosion aboard President Yameen's speedboat on Sept. 28 that wounded his wife and two others.
Yameen was unharmed, and the US Federal Bureau of Investigation has said there is no evidence it was caused by a bomb.
But authorities in the Maldives have called it an attempt on his life. On October 24 Yameen arrested his deputy, Ahmed Adeeb, accusing him of “high treason” and linking him to the boat blast.
This week the Maldivian National Defense Force said it had found a remote-controlled bomb near the president's official residence and defused it.
Over a third of the country's 340,000 Sunni Muslim population lives on the capital island Male, where authorities said the device was found.
Yameen has used allegations of an assassination plot to order a major shake-up of his security. He sacked several of his ministers before arresting Vice President Adeeb, who is also due to be impeached.
Yameen's former vice president and running mate in the November 2013 election, Mohamed Jameel, was impeached in July while he was abroad and has not returned to the country.
On Wednesday Jameel accused Yameen of using emergency laws to try to crack down on the opposition.
"Emergency is a ploy to halt planned opposition rally. Nothing to justify this measure," he tweeted.
The Maldives' image as a luxury holiday destination has been badly dented by political unrest in recent years.
Yameen, who came to power in November 2013 following a controversial election, faces international censure over his crackdown on opponents of his regime.
They include opposition leader Nasheed, the country's first democratically elected leader, who was jailed in March after a rushed trial which the United Nations said was seriously flawed.
The MDP rally in the capital is aimed at pressuring Yameen to release Nasheed, whose incarceration has been severely criticized by the UN and international rights groups.
U.S. Secretary of State John Kerry spoke in May of "troubling signs" for democracy in the Maldives, while Indian Prime Minister Narendra Modi this year shelved plans to visit the islands, a move seen as a rebuke to Yameen.
Despite the political unrest, tourism — the archipelago's mainstay — is booming with more than one million visitors a year.
Holidaymakers paying top dollar to relax on one of the atolls are usually whisked away by seaplane or boat, bypassing the restive capital where extra police have been deployed in recent months.