HANOI, Vietnam — Vietnamese authorities sentenced an influential YouTuber and campaigner who spoke out on pollution and land rights to five years in jail on an anti-state charge on Thursday, his lawyer said.

Nguyen Chi Tuyen was found guilty of "making, storing and disseminating information, documents and materials against the Socialist Republic of Vietnam" and jailed for five years in Hanoi, lawyer Nguyen Ha Luan told Agence France-Presse.

Tuyen — who is also known as Anh Chi — helped found the football club No-U FC, whose members protested China's territorial claims in the South China Sea, where Vietnam also has claims.

He was outspoken on sensitive social issues in Vietnam, including environmental pollution and land disputes, as well as on global conflicts such as the war between Russia and Ukraine.

One of his YouTube channels, Anh Chi Rau Den, has 1,600 videos uploaded and 98,000 subscribers.

Analysts say authorities in communist Vietnam have escalated a crackdown on dissent in recent years.

Prior to the trial, Human Rights Watch (HRW) called on Vietnamese authorities to free Tuyen.

"Vietnam's authorities have targeted Nguyen Chi Tuyen for expressing views they don't like," said Patricia Gossman, associate Asia director at HRW.

"The government should stop jailing peaceful critics, repeal its draconian penal laws, and end the systematic violation of basic rights," she added.

Tuyen said on social media that he had been subject to police harassment, physical attacks, house arrest, and an international travel ban.

"We did not fight, did not try to win things from anybody," he wrote on Facebook in April last year.

"We only acted in accordance with our conscience, speaking our thoughts, voicing our desires and aspirations."

Tuyen was arrested late February on the same day as Nguyen Vu Binh, a political activist who had served almost five years in jail in the early 2000s. No trial date for Binh has been announced.

According to HRW, since 2016, Vietnamese police have arrested at least 269 people for peacefully exercising their basic civil and political rights.

In April last year, Nguyen Lan Thang, a friend of Tuyen who was also a member of the No-U FC team, was jailed for six years on a similar charge.

Thang was a prominent freelance journalist who documented protests and human rights violations.