A Vietnamese court Wednesday sentenced a French-Vietnamese activist to three years in prison on charges of subversion.

Pham Minh Hoang was convicted after a half-day trial of “carrying out activities aimed at overthrowing the people's administration.” Authorities say he posted several anti-government articles on the Internet, and had ties to Viet Tan, a U.S.-based pro-democracy group that is banned in Vietnam.

Hoang's wife said she believes her husband was being held due to his opposition to a Chinese-run bauxite mine in the Central Highlands, which activists say has caused environmental degradation in the area.

Hoang is a Vietnamese-born math professor who lived for several years in France, and holds French citizenship.

Wednesday's sentencing triggered condemnation from Paris and from Amnesty International. The French Foreign Ministry called for an immediate judicial review of Hoang's sentencing, and said he should be released as soon as possible.

Amnesty called the verdict and the prison term “outrageous,” while the media advocacy group Reporters Without Borders (Reporters Sans Frontieres) described Hoang as “a citizen who just expressed his views.”

Hoang is set to receive credit for the one year he has already spent in detention awaiting trial. But he faces another three years of house arrest following the end of his prison term.