BEIJING -- A Beijing court on Sunday sentenced a legal scholar and founder of a social movement to four years in jail for disrupting order in public places, in a case that the U.S. government and other critics say is retribution against his push to fight corruption and create equal educational opportunities.

Amid tight security, the Beijing No. 1 Intermediate People's Court handed down the verdict against Xu Zhiyong, founder of the loosely knit New Citizens movement, in a blow to the movement and China's rights activism.

Hundreds of police officers -- both in uniform and in plainclothes -- were stationed around the courthouse. They pushed away journalists and took away Xu's lawyer when he attempted to speak to the media, but not before he denounced the process as "very unfair."

Xu's prosecution is part of a broader crackdown since last spring on dissent, including the silencing and detentions of influential bloggers and advocates for minority rights in Tibetan and Muslim Uighur areas.

Earlier this month, the authorities took away Ilham Tohti, a Uighur scholar and outspoken critic of China's ethnic policies. A police statement accused the university professor of separatism, inciting ethnic hatred and advocating violence to oppose China's rule over the far west region of Xinjiang, home to the ethnic minority of Turkic-speaking Muslim Uighurs.

The ruling Communist Party is wary of any form of social force such as Xu's New Citizens movement because of its potential to threaten the party's rule at the grassroots level. Several other activists have stood trial or are scheduled to appear in court -- all on the same charge of disrupting public order, and their prosecutions have clipped the movement, rights lawyer Zhang Xuezhong said.

"There are no longer any members with influence and ability to take action," Zhang said. "It is hard to say if anyone who has not been arrested can rise up to take over."

Amnesty International on Sunday called the jailing a travesty. "This is a shameful but sadly predictable verdict," East Asia Research director Roseann Rife said in a statement. "The Chinese authorities have once again opted for the rule of fear over the rule of law."

"Xu Zhiyong's calls for justice and accountability are entirely legitimate. He is a prisoner of conscience and he should be released immediately and unconditionally," Rife said.

Xu and his followers purposely kept the movement unstructured so as not to challenge the party's zero intolerance on organized movements. They downplayed any political appeals and championed causes that were in line with the party's own stated goals.

Still, Xu's fledgling New Citizens movement became a target after it inspired people across the country to gather for dinner parties to discuss social issues and occasionally to unfurl banners in public places in small rallies.

Last year, a document purportedly circulated by the Communist Party's top leadership warned of the dangers of citizen movements, saying they would eventually form a political opposition force to challenge the party at the grassroots level.

The document characterizes citizens' calls for public disclosure of officials' assets as a tactic by anti-China forces in the West and dissidents at home to incite discontent.

During his closed-door court hearing on Wednesday, Xu refused to respond to the prosecutors to protest what he said was an unfair trial. Instead he read out a lengthy manifesto-like closing statement for about 10 minutes before he was cut off.

"Our actions did not violate the rights of any other person, nor did they bring harm to society," Xu said, according to a copy of the speech released by his lawyers.