They are released at the end of the day after attempting to honor Vietnamese killed in a 1979 border war.
Some members of the three families that have left the country vow to drown themselves at sea if they are returned again.
Human rights groups and individuals seek the release of Tran Thi Nga.
The protests over compensation caused the commune and village chiefs to flee.
Nguyen Van Hoa is known for filming protests against the Formosa steel plant.
In the latest incident, police block a group of priests from attending a church service in the city of Hue.
Tran Thi Nga and three others are reported to be arrested in a crackdown on dissent.
Violent clashes mark attempts to memorialize a 1974 island grab by China that cost the lives of 75 Vietnamese.
Dang Xuan Dieu was released from prison, as authorities stopped Pham Thanh Nghien at the border with Cambodia.
The human smuggling arrests come as Hanoi says human trafficking jumped in 2016.
The Formosa steel mill disaster devastated the country's central coast, killing hundreds of tons of fish and sparking protests, lawsuits, and arrests.
Shrimp paste and paint are smeared on Tran Thu Nam's home.
A coroner’s report says that Pham Dang Toan died because he ran, not because police beat him.
An expansion of the ‘Magnitsky’ act gives Washington a new legal tool.
At least two men are beaten and one was threatened with a gun as police and thugs break up the session.
Nguyen Van Dai's time in prison is extended for the third time as he faces charges of 'conducting propaganda against the state.'
Experts criticize the hydropower companies and the government for failing to heed warnings and take action.
The “National Force to Launch the Democracy Flag” group had only six members, but two were well-known for their views.
Convictions for ‘organizing for others to flee the country illegally’ come under a new law as Canberra and Hanoi sign immigration agreement.