A Vietnamese music teacher has been arrested for posting material on Facebook "aimed at undermining" the state, his family and official media said Thursday in the communist country where a crackdown against online critics has gathered pace.
Activists, rights lawyers and bloggers have long been targeted in the one-party state where independent media and public protests are banned, with critics increasingly moving onto social media to voice discontent.
Amnesty International says there are currently 128 prisoners of conscience behind bars in Vietnam. About 10 percent of them were jailed for online commentary on platforms like Facebook.
Nguyen Nang Tinh was arrested for "producing, disseminating or spreading information and documents aimed at undermining" Vietnam, according to the official police newspaper in central Nghe An province where he was detained.
His father said Tinh was bundled into a car by police after taking his two young sons for breakfast on Wednesday morning.
"Police later phoned me so that I could go there and pick up the boys," Nguyen Dang Dinh told AFP, adding that he is barred from visiting him in jail.
Tinh is accused of posting "hostile thoughts" and "profound anti-government material" on his Facebook page, according to the Nghe An police newspaper.
He was accused of having links to "reactionary activists inside and outside" the country, the report said.
The 42-year-old teacher allegedly posted about Viet Tan, a US-based activist group that Vietnam has labelled a terrorist organization.
His wife said Tinh, who teaches piano, organ and music theory at a local college, did not belong to Viet Tan and should not have been jailed.
"He raised his voice only for those who were mistreated… he never thought for himself, he only acted for the people," Nguyen Thi Tinh told AFP.
She said he posted about a 2016 environmental disaster involving a Taiwanese steel company that dumped toxic sludge into the ocean, killing tonnes of fish and destroying the livelihoods of fishermen along the central coast.
Tinh could be held for several months until he is formally charged and faces up to 20 years in jail if convicted.
Vietnam has faced a chorus of criticism for a crackdown on activists since 2016 when a hardline administration took charge.
Last year the country passed a controversial cybersecurity law that requires Internet companies like Facebook and Google to hand over user data and remove content if requested by the government to do so.
Amnesty International decried Tinh's arrest and called for his immediate release.
"His so-called crime is just to have a peaceful political opinion," Amnesty's Vietnam campaigner Nguyen Truong Son said.