The one-party state has long locked up lawyers, activists and bloggers it deems critical, but rights groups say a conservative leadership in place since 2016 has hardened a crackdown on dissent that shows no signs of letting up.

Vu Quang Thuan and Nguyen Van Dien were convicted yesterday after posting 17 videos online that were critical of the government, their lawyer Le Luan said.

Thuan, 51, has already been to jail twice for anti-state activity and was given eight years in prison, while 34-year-old Dien was sentenced to 61/2 years. Both were arrested in March last year.

"They were found guilty of spreading propaganda against the state," Mr Luan said.

Law graduate Tran Hoang Phuc, 23, was also sentenced to six years in jail on the same charge for helping the pair store material and post some clips.

"Phuc only helped the men with technical assistance, so it was groundless to charge him with anti-state propaganda," Mr Luan said.

The men's lawyers asked for the videos to be broadcast in the court, but the request was denied by court officials citing technical issues.

Phuc was invited to meet former US president Barack Obama in 2016 during a visit to Vietnam, but was taken away by security officers before the meeting, according to Human Rights Watch (HRW).

He was later released, but has been in detention since June last year.

Thuan and Dien had previously spent time in Malaysia, where they were involved in rights activism.

HRW reports that Thuan tried to self-immolate in Kuala Lumpur in 2010 while protesting against Malaysia's deportation of two Vietnamese dissidents.

The rights group called for the authorities to drop charges against the three men ahead of the trial, and said it should not silence activists.

"Arrest and imprisonment of dissenting voices will not stop the increasing number of Vietnamese from speaking up," HRW Asia director Brad Adams said in a statement.

All independent media is banned in Vietnam, and activists have increasingly moved online to voice discontent despite an uptick in arrests and convictions in recent years.

At least 24 activists were convicted last year, with another 28 arrested, according to HRW. They join scores of dissidents already behind bars.

Agence France Presse - February 1st, 2018