A diplomatic source has told media outlets that so far two people have been sentenced in the closed-session trials in Hanoi and the port of Haiphong, including a former school teacher.
The unnamed source said Vu Hung, 43, was sentenced to three years for, most notably, hanging a banner around 10 feet long over a Hanoi bridge in July 2008 upon which he demanded multiparty democracy.
Vu Hung along with several other activists was arrested in September last year on charges of spreading propaganda against the state, according to human-rights group Amnesty International.
A poet, Tran Duc Thach, has also been sentenced to three years in prison and seven more activists will face trial later this month, according to brief media reports.
The judge reportedly said Vu Hung, a high school physics teacher before his arrest, was a danger to society. Vu Hung's comment was simply that he wanted only for his voice to be heard.
Amnesty International has been calling for their release from prison since last year and has been compiling information about their physical and mental condition from fellow prisoners who have been set free.
Vu Hung, married with two children, was causing most concern to Amnesty because of reports of his ill health, several visits to hospitals and alleged beatings. His whereabouts while in prison were not known for two months before the trial began this month.
He is also one of 14 people arrested in April 2008 during peaceful demonstrations against Chinese policies as the Olympic torch relay passed through Ho Chi Minh City. He was then beaten by police before being released, Amnesty said.
The current trials are the latest in a series that the government has been pursuing since the protest movement Bloc 8406 was created three years ago.
Since then Amnesty believes at least 30 dissidents have been handed long prison sentences, and an unknown number of dissidents are languishing in jail under what is called pre-trial detention.
In 2006 the government liberalized Web access in the country but found it being used for protest purposes. An initial clampdown only increased the use of the Web as a vehicle for protest, particularly by Bloc 8406 members and supporters.
Bloc 8406 is a loose coalition of political activists and pressure groups within Vietnam who advocate for democracy reforms. The name comes from the date of the Bloc 8406 democracy manifesto, on April 8, 2006.
Originally it was signed by 118 dissidents calling for a multiparty state, but support has grown into the thousands, analysts have said. A prominent supporter is longtime activist and Catholic priest Nguyen Van Ly, 64.
The communist government has considered Van Ly a thorn in its side since it took control of the country in 1975. He was sentenced in March 2007 to eight years in prison for his support of Bloc 8406.
The protest group's trademark is that of a brief video clip on the Web where people, old and young, are interviewed, often in the streets and holding up protest signs with "Freedom" written in English.