The four men were members of a democracy group founded by jailed lawyer Nguyen Van Dai.
They call on the government to release Tran Thi Nga, who was sentenced to nine years’ imprisonment and five years’ house arrest for ‘conducting anti-state propaganda.’
Le Dinh Luong is accused of membership in the banned U.S.-based opposition party Viet Tan and other anti-state activities.
Residents say they disagree with the ruling and call for dialogue.
Tran Thi Nga is sentenced for conducting 'propaganda against the state' under a law widely used to silence dissent.
China’s warning comes days after the confirmation of a major gas field in the area.
The crewman is the third to die as a hostage of Abu Sayyaf in the last week.
The government kept relatives in the dark about the hostage situation, sources say.
The severed heads of two men were lying near their bodies, officials say.
Tran Hoang Phuc, 23, was detained on July 3 under article 88 of Vietnam's penal code
About 1,000 parishioners from Quang Binh province demand payouts from local administrators for the loss of livelihoods they have suffered.