Authorities charged Nguyen Xuan Nghia and five associates after jailing them in September 2008, the newspaper said.

Police completed their investigation amid Vietnam's latest crackdown against dissidents. Over the last month, they have arrested at least five other pro-democracy activists on similar accusations, underlining the government's refusal to tolerate any challenges to its one-party rule.

Authorities say Nghia was a member of Bloc 8406, an outlawed pro-democracy group founded in 2006 by jailed Catholic priest Thadeus Nguyen Van Ly, the Labor newspaper said.

The 60-year-old novelist is from the northern port city of Haiphong. Authorities say he authored 57 articles between 2007 and his arrest last year that defamed the Communist Party and its leaders and incited people to oppose the government, the newspaper said.

He and five associates are also accused of hanging anti-government posters on busy bridges in Haiphong and the neighboring province of Hai Duong and posting photos of them on the Internet, the paper said.

The Foreign Ministry did not immediately respond to a request for comment Tuesday.

Last month, authorities arrested Le Cong Dinh, a well known human rights lawyer, and accused him of collaborating with overseas groups to incite anti-government sentiment. At least four others have been arrested in connection with Dinh's case, two of them last week.

Western governments and international human rights groups have often criticized Vietnam for jailing people for peacefully expressing their views. Hanoi says it only imprisons people who break the law.