Vietnam sentenced a pro-democracy activist to five years in prison, the sixth to be jailed in less than a week.
Tran Quoc Hien, 42, an attorney, was convicted of spreading anti-government propaganda and disrupting security, Ho Chi Minh City People's Court officials said. Hien must also serve two years' probation after his prison sentence.
Hien's conviction after a four-hour trial came just days after Vietnam sent five other dissidents to prison for up to five years for spreading propaganda against the state.
Like several of those convicted last week, Hien was accused of participating in Bloc 8406, an organization that wrote a pro-democracy manifesto and circulated pro-democracy petitions in Vietnam last year.
He was also charged with trying to organize anti-government demonstrations in Ho Chi Minh City last fall during an international summit attended by U.S. President George W. Bush.
Western governments have decried the trials, saying the dissidents were being punished simply for exercising their right to free speech.
"The EU reiterates its plea to the government of Viet Nam to release all non-violent political activists who have simply exercised their rights to freedom of expression and association," Germany, which holds the European Union Presidency, said in a statement.
The day before Hien's trial began, the Foreign Ministry issued a statement dismissing such criticism as groundless.
"As we have said time and time again, the Vietnamese government has always respected the rights to freedom and democracy, including the freedom of speech," the statement said.
"In Vietnam, no one is arrested due to their political or religious beliefs," it continued. "Only those who have breached the law are punished."
Vietnam's communist government does not tolerate challenges to its single-party rule.
Last week, Vietnam sent five pro-democracy activists to prison in two separate trials. They were accused of collaborating with overseas pro-democracy activists and trying to organize independent political organizations.
New York-based Human Rights Watch has described Vietnam's latest crackdown on dissent as one of the worst in two decades.