The UN human rights chief has said the declaration of a state of emergency in the Maldives and the resulting suspension of constitutional guarantees amounts to an “all-out assault on democracy”.

Political turmoil has swept the Maldives since a surprise court ruling last week ordered the release of jailed opposition leaders, including many of President Yameen Abdul Gayoom’s main political rivals. He imposed a state of emergency on Monday.

UN high commissioner for human rights Zeid Ra’ad al-Hussein said the restrictions “create a dangerous concentration of power in the hands of the president”.

The Maldives became a multi-party democracy 10 years ago, but lost much of those gains after Mr Yameen was elected in 2013.

Mr Zeid said Mr Yameen “has, to put it bluntly, usurped the authority of the state’s rule-of-law institutions and its ability to work independently from the executive”. What is happening now, he said, “is tantamount to an all-out assault on democracy”.

The commissioner’s criticism came a day after three Maldives supreme court justices annulled their earlier order to free the imprisoned opposition politicians after two of the court’s justices were arrested.

The annulment came after Mr Yameen declared the state of emergency, which gives officials sweeping powers to make arrests, search and seize property and restrict freedom of assembly.

The UN and many foreign governments including the US, UK and India have expressed concern over the state of emergency in the Indian Ocean archipelago nation and have urged Mr Yameen to respect the earlier court order.

Hours after the emergency was declared, security forces in riot gear stormed the supreme court building and arrested the two judges, including Chief Justice Abdulla Saeed. It is not immediately clear what charges they will face, if any.

Security forces also arrested former dictator and opposition politician Maumoon Abdul Gayoom. His lawyer, Maumoon Hameed, said Mr Gayoom faced charges including bribery and attempting to overthrow the government.

Mr Gayoom was president from 1978 to 2008, when the Maldives became a multi-party democracy.