A Vietnamese court has jailed a former journalist at a Communist Party magazine for seven years on espionage charges, capping a string of crackdowns on critics of the government.

Nguyen Vu Binh, 35, had called for political reform.

"Binh has been sentenced to seven years in prison for the crime of spying," said an official at the Hanoi People's Court.

It was unclear whom Binh was accused of spying for.

The official declined to say whether Binh would be subject to a period of house arrest after serving his jail term, as if often the case with political detainees in Vietnam.

The trial took place under tight security, with media and diplomats denied access. A heavy security presence at the courthouse on Wednesday kept observers behind barricades.

"The sentence could have been worse," a Western diplomat in Hanoi said, adding that the sentence might be reduced on appeal.

The diplomat added, however: "It's an unfortunate development. He shouldn't be in prison at all."

Binh was arrested in September 2002 after criticising a border treaty with China in an article distributed on the Internet, Human Rights Watch said.

Binh, who worked for nearly 10 years at the Communist Party's Communist Review, had also signed a group petition urging Hanoi to carry out political reforms, and had sought to form an independent political party, rights groups say.

Last June a doctor, Pham Hong Son, was sentenced to 13 years in prison for espionage after he translated into Vietnamese a U.S. State Department essay on democracy and posted it on the Internet. His term was later cut to five years.

Two dissidents were jailed last year for cyberspace criticisms of Hanoi.

Binh's case parallels those of lawyer Le Chi Quang and literature professor Tran Khue, sentenced after criticising the border pact with China which some say gave up too much land to Vietnam's giant northern neighbor.

The former journalist and 16 others had sent an open letter to top leaders calling for the release of Quang and Son.

CNN News

Good artists copy, great artists