Religious freedom is further at risk in the Maldives after the Indian Ocean archipelago legalised criminal defamation on Tuesday.

The move has been strongly criticised by the UN, rights groups and Western nations including the US and Britain. The opposition has warned that President Abdulla Yameen's administration is trying to stifle dissent.

The law criminalises defamatory speech, remarks, writings and other actions including a gesture and targets actions against "any tenet of Islam" in the Muslim-majority country.

The bill was passed by a 16-vote majority led by Yameen's ruling Progressive Party of Maldives.

Those found guilty will be fined between 50,000 Maldivian rufiya ($3,200) and two million rufiya ($130,000) or face a jail term of between three and six months.

Publications, including websites, found carrying "defamatory" comments could also have their licenses revoked.

"So basically it's crippling freedom of expression including on the basis of defamation of religion, national security and social norms," said Mona Rishmawi, chief of the Rule of Law branch at the UN human rights office.

US State Department spokeswoman Elizabeth Trudeau said yesterday the defamation bill was a "serious setback for freedom of expression".

"The United States values freedom of expression as a key component of democratic governance. Democratic societies are not infallible, but they are accountable, and a free exchange of ideas is the foundation for accountability," she added.

"We continue to express our support for all Maldivians struggling to preserve their hard won democratic institutions and rights," she said.

The Maldives became a multi-party democracy in 2008 after decades as an autocratic state, but former President Mohamed Nasheed, its first democratically elected leader, was ousted in disputed circumstances in 2012.

Since then, campaigners have expressed concern that the country is sliding back to autocracy. Nasheed was sentenced to 13 years in prison in March 2015 under the Anti-Terrorism Act, but was this year granted asylum in the UK.

The Maldives ranks 13^th on persecution charity Open Doors' list of countries where it is most dangerous to be a Christian. It is illegal to "propagate any religion other than Islam" and breaking this law can result in a prison sentence of up to five years.

Maldivian Christians are forced to practise their faith in secret, and migrant Christians living in the country are closely monitored.

Additional reporting by Reuters.