BANGKOK (AFP) -- Authorities in Vietnam have arrested a leading independent journalist for "abusing democratic freedoms" to undermine the state by posting articles on Facebook, police announced on Saturday.

Huy Duc was detained for investigation for posts that "violate the interests of the State, the legitimate rights and interests of organizations and individuals," the Ministry of Public Security said.

The 62-year-old former senior lieutenant worked for several influential newspapers in Vietnam before being fired in 2009 for criticizing the country's former communist ally the Soviet Union.

Shortly before his arrest, Duc took aim at Vietnam's new president To Lam, as well as Nguyen Phu Trong, the communist party general secretary and most powerful individual in the country's political system.

Lawyer Tran Dinh Trien was held along with Duc on the same charges.

Communist one-party Vietnam has strict curbs on freedom of expression, and Reporters Without Borders (RSF) ranks it 174th out of 180 countries for press freedom, describing it as one of the world's worst jailers of journalists. Duc's blog, one of the most popular in authoritarian Vietnam, was highly critical of government responses on issues including control of the media, relations with China, and corruption.

Duc, whose real name is Truong Huy San, spent a year at Harvard University on a Nieman Fellowship in 2012. During his time abroad, his account of life in Vietnam after the end of the war with the United States, "The Winning Side," was published. RSF called for his release.

"The articles of independent journalist Huy Duc are an invaluable source of information enabling the Vietnamese public to access censored information by the Hanoi regime," RSF Asia-Pacific Bureau Director Cedric Alviani said in a statement.

Rights campaigners say the government has in recent years stepped up a crackdown on civil society, while thousands of people, including several senior government and business leaders, have been caught up in a massive anti-graft campaign.

"No country can develop sustainably based on fear," Duc wrote on Facebook in May.