A French-Vietnamese activist is on trial in Vietnam on charges of subversion.

Pham Minh Hoang is accused of “carrying out activities aimed at overthrowing the people's administration.” Authorities say he posted several anti-government articles on the Internet, as well as having ties to Viet Tan, a pro-democracy group that is banned in Vietnam.

Hoang's wife says she believes her husband is 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.