Nghien was also sentenced to three years under house arrest at the trial in the northern city of Haiphong, her lawyer told the BBC.

She was the latest of several Vietnamese dissidents to receive harsh sentences in recent weeks.

Last week four activists were jailed on charges of subversion.

Nghien was arrested in September 2008 after criticising Vietnam's policies towards China over disputed maritime claims.

She had displayed two banners at her home and posted pictures of the protest on the internet.

But those charges were dropped before the trial and she was tried for her writing and interviews with foreign media groups in which she criticised the government.

The BBC's Nga Pham in the region says the guilty verdict was largely expected and has been seen as part of a large crackdown on activism.

Clampdown criticism

Nghien - who was given an award by US-based Human Rights Watch (HRW) in 2008 for her pro-democracy activism - was charged under Section 88 of the penal code, which critics say criminalises peaceful dissent.

The one-day trial was closed to western media and diplomats and her lawyers said her mother was also prevented from attending.

Her conviction comes a week after four people, including prominent human rights lawyer Le Cong Dinh, were found guilty of trying to overthrow the Communist government.

The four men received sentences of up to 16 years on charges of subversion.

Our correspondent says the trials show a concerted effort by the government to send the message that no form of political dissent will be tolerated, especially with an important Communist Party Congress due next January.

BBC News - january 29, 2010

Vietnam sentences democracy activist to 4 years

An author and democracy activist who criticized Vietnam's communist government was sentenced Friday Jan 29 to four years in prison on charges of spreading propaganda against the state, her lawyer said.

Pham Thanh Nghien, 32, was also given three years' probation after a half-day trial in the northern port city of Haiphong, attorney Tran Vu Hai said.

The trial was closed to Western media and diplomats, who are ordinarily allowed to watch such proceedings on closed-circuit TV at the courthouse.

Nghien is the 15th Vietnamese democracy activist to face charges in the last three months. All the others were quickly tried, convicted and jailed.

Last year, US-based Human Rights Watch gave Nghien an award for writers who have been targets of political persecution. It praised articles she wrote promoting human rights, democracy and better treatment of landless peasants.

Nghien, an independent journalist, was arrested at her home in September 2008 and originally accused of staging a protest against the Vietnamese government's policies toward China, its massive northern neighbor.

She displayed two banners urging the government to take a tougher stance against China in territorial disputes over the Spratlys and Paracels, two island chains in the South China Sea. She was also accused of posting photographs of her protest online.

But on Friday, prosecutors withdrew those charges and her conviction was based on a separate incident, her lawyer said.

Prosecutors argued that she had defamed officials by writing an article in which she alleged they had stolen money intended for relatives of fishermen who had been killed by Chinese patrols in a 2007 incident, Hai said.

Nghien was also charged with possessing anti-government documents written by other dissidents and giving interviews to Western media.

In her testimony, Nghien acknowledged she committed those acts but maintained that they were not illegal, Hai said.

By Ben Stocking - The Associated Press - January 30, 2010