An environmental activist has been jailed for six years in Vietnam for “anti-state” Facebook posts, as part of the country’s continuing crackdown on social media.

Nguyen Ngoc Anh, a shrimp farming engineer, was sentenced to six years in jail for “making, storing, disseminating or propagandising materials and products that aim to oppose the state of the Socialist Republic of Vietnam”, related to a series of Facebook posts from last year.

Nguyen was arrested in September for sharing and writing Facebook posts which allegedly urged people to take part in peaceful protests in June.

He had also voiced criticism about the controversial Formosa environmental disaster in 2016, which saw a Taiwanese steel company dump toxic waste into the ocean near the coast of Hà Tĩnh and three other provinces in central Vietnam, killing millions of fish.

According to reports, Nguyen’s posts received upwards of 45,000 likes.

Since 2017, Vietnam has been escalating its arrests of bloggers and social media activists who criticise the government or draw attention to environmental issues.

Nguyen’s conviction brought condemnation from the European Union, which released a statement through their foreign service stating: “Nguyen Ngoc Anh’s right to peaceful freedom of expression is guaranteed by the Vietnamese constitution.”

Amnesty International said the “sham trial” was just the latest evidence that Vietnam’s repressive communist government was increasing its chokehold on civil society by targeting posts on Facebook.

Nicholas Bequelin, a regional director at Amnesty International, said: “The sham charges levelled against Nguyen Ngoc Anh show that no one is safe on Facebook in Vietnam any more. Anh is only the last case in a growing list of netizens prosecuted, arrested or detained solely for peacefully discussing public affairs or criticising the government.”

An estimated 55 million people in Vietnam use social media regularly, ranking seventh in the world for social media engagement, but it is governed by restrictions similar to those in China limiting freedom of expression online.

As part of a draconian new cybersecurity law that came into effect in January this year, Facebook, Google and other technology firms are required to locally store “important” personal data on users in Vietnam, which they then have to hand over to the government.

The Vietnam government accused Facebook of violating the law this year by allowing users to post anti-government sentiments on the site.