A Vietnamese blogger has been arrested for anti-state activity, reports said Sunday, the third online government critic detained in less than a month in an intensifying crackdown on dissent.

Dinh Nhat Uy, 30, was taken into custody Saturday and will be held for three months while he is investigated on suspicion of “abusing democratic freedoms to infringe on the interests of the State”, the official Vietnam News Agency (VNA) said. 

The charge — routinely laid against dissidents in authoritarian Vietnam where the ruling Communist Party forbids all political debate — carries a maximum seven year jail term.

Uy is the brother of computer technician Dinh Nguyen Kha, 25, who was jailed for eight years at a trial in May together with university student Nguyen Phuong Uyen on charges of spreading anti-state propaganda, the VNA report said Sunday.

Investigators have accused Uy of “posting pictures and articles on his personal blog, distorting the truth and badly influencing the prestige of state organisations”, the report added.

Uy was known in Vietnam’s underground activist circles for his strong opposition to perceived aggression by China in the disputed South China Sea — known in Vietnam as the East Sea.

He is the third blogger in less than a month to be detained on the same charge, following the detention of former government official turned activist Pham Viet Dao on Thursday, and high-profile blogger Truong Duy Nhat in late May.

Dozens of activists have been jailed since the one-party state began a new crackdown on free expression in late 2009.

Vietnam bans private media and all newspapers and television channels are state-run. Lawyers, bloggers and activists are regularly subject to arbitrary arrest and detention, according to rights groups.

So far in 2013, at least 46 activists have been convicted of anti-state activity and sentenced to often lengthy jail terms under what rights groups say are vaguely defined articles of the penal code.