Maldives President Abdulla Yameen on Sunday described his deputy as a threat to national security after his arrest over an alleged attempt to assassinate Yameen in a speedboat bombing last month.

Soldiers and police patrolled the capital Male's streets in stepped up security, one day after vice president Ahmed Adeeb was arrested as he arrived back in the honeymoon islands from an official trip abroad.

A United Nations panel has ruled that the jailing of former Maldives president Mohamed Nasheed was illegal and called for his immediate release, the government of the atoll nation said Thursday as it rejected the ruling.

The government said it had received a copy of the U.N. Working Group on Arbitrary Detention (WGAD) ruling, which has not yet been made public, and which follows a complaint by the country's first democratically elected leader.

An explosion ripped through a speed boat carrying Maldives President Abdulla Yameen on Monday, injuring his wife and two others but leaving him unhurt, a minister said.

It is not clear what caused the blast on the presidential craft as it docked in the capital island Male.

The United States pressed the Maldives Wednesday to release former leader Mohamed Nasheed after he was returned to prison despite a court order commuting his 13-year term to house arrest.

U.S. assistant secretary for South Asia Nisha Biswal said Washington was concerned about a move away from democracy in the Indian Ocean archipelago, a popular tourist destination.

The return to prison of former Maldives president Mohamed Nasheed is a setback for human rights in the country, the U.N. said Tuesday, calling on the island nation's government to consider his early release.

Just a month after Nasheed's 13-year prison sentence was commuted to house arrest, he was taken back to jail on Sunday night, as police used force and pepper spray on the ex-president's supporters gathered outside his home, the U.N. rights office (OHCHR) said.

The Maldives has put former president Mohamed Nasheed back in jail a month after his 13-year prison sentence was commuted to house arrest, sparking clashes between his supporters and police in the honeymoon island nation.

Nasheed's Maldivian Democratic Party (MDP) said police and prison officials clashed with its supporters as they removed him from his home in the capital Male and took him to the high-security prison island of Maafushi on Sunday night.

A Malaysian team inspecting debris that washed up in the Maldives has so far found nothing that came from missing flight MH370, Malaysia's transport minister was quoted as saying on Friday.

Malaysia sent experts to the Maldives this week to check on reported debris found on the coral atoll nation after a wing part from the ill-fated plane was found on Reunion island in the Indian Ocean to the south.

Malaysia will send a team to the Maldives to determine whether debris reportedly found there is further wreckage from flight MH370, the transport minister said Monday.

Transport Minister Liow Tiong Lai said Malaysia had been "officially notified" by authorities in the Maldives of objects found there, whose origin remains unverified.

The Maldives joined a regional search for wreckage from missing flight MH370 following reports that islanders in the Indian ocean atoll nation had spotted unidentified debris, police said Sunday.

Maldivian police are responding to several sightings of debris washed up along the northern atolls of the archipelago, some of which occurred about a month ago, a police spokesman said.

The Maldives parliament has sacked the country's vice president and accused him of treason, as international concern mounts over the state of democracy on the honeymoon islands.

Lawmakers voted overwhelmingly on Tuesday evening to oust Mohamed Jameel, who was the running mate of President Abdulla Yameen in a controversial 2013 election but has now fallen out with him.