It quoted an April 13 report in a state-run newspaper as saying the People's Court in Ha Tinh province sentenced Teresa Tran Thi Xuan to nine years in prison April 12 for "attempting to overthrow the people's government."

Xuan, 42, also faces another five years under house arrest after finishing what observers called a very harsh sentence.

The newspaper said Xuan shared articles and video clips on social media from "reactionary groups" to undermine the government.

She also was accused of organizing protests at the local government headquarters against the Taiwanese steel firm Formosa, which was responsible for a massive toxic waste spill in the province. During the protests, in April 2017, she incited people to damage public property and cause social disorder, the court said.

Xuan comes from Loc Ha, a local district badly affected by the toxic spill.

The court was told the activist was a member the Brotherhood for Democracy, a domestic civil society organization that the government sees as a reactionary group trying to overthrow the communist state.

Security was tight outside the courthouse with a strong police presence, witnesses said.

Xuan's relatives were only informed about the trial -- which lasted two hours -- when it was nearly over, said a source who did not wish to be named. He said Xuan's sentence was harsh and that she was being punished for helping elderly and poor people and opposing a social injustice created by the authorities.

In a two-week period in late March and early April, Vietnam jailed 10 activists, sentencing them to terms totaling 96 years, ucanews.com reported.