BEIJING (AP) -- Chinese authorities have shut down or frozen the microblog accounts of several prominent liberal intellectuals and harassed rights lawyers lobbying against unofficial "black jails," underlining the determination of the country's new leadership to control dissent even as it vows to root out corruption.
The moves over the last few days occurred around the time officials announced that a senior official was being investigated for graft, months after a prominent journalist accused him of wrongdoing. The probe against Liu Tienan, deputy chairman of China's economic planning agency, was heralded by the Chinese press as proof that the battle against corruption is best fought when authorities allow public participation.
"The authorities and the people combined their strengths in this case, and it is an encouragement to the public's power in fighting corruption," said a state-run daily, the Beijing News, in a commentary.
The government issued a defense of its human-rights policies in a report Tuesday, outlining progress made in improving health, welfare and other living standards -- a key measure the government uses in its definition of rights. The report said China takes measures to ensure the "citizens' right to know and right to be heard."
But the authoritarian government also has shown an unwavering intent to clamp down on anyone who seeks to publicly pressure it into social or political change. The message appears to be that if any reform is on the agenda, the Communist Party will push it through on its own terms.
"The controls are tighter than ever," said Li Cheng, an expert on China's elite politics at the Washington-based Brookings Institution. "The challenges are greater, so the suppression is escalating."
Small groups of activists have been detained in Beijing and other cities for holding banners calling for officials to publicly declare their assets -- a key anti-graft measure that the government has been reluctant to implement. One activist, Liu Ping, has been accused of inciting subversion, a vaguely worded charge frequently used to suppress dissidents.
Authorities are also maintaining a years-long effort to quash legal activism.
On Monday, several rights lawyers attempting to visit one of China's unofficial detention centers -- also known as "black jails" -- in the southwestern city of Ziyang were beaten by unidentified men, said Beijing attorney Li Heping, who was contacted by one of the lawyers.
The efforts to police discourse are also being ramped up in the Chinese blogosphere, where users often challenge the government's version of events and its control over information.
Over the weekend, authorities apparently removed all microblog accounts belonging to the writer Hao Qun, better known by his pen name Murong Xuecun, from four different sites. His subsequent efforts to set up new accounts have been blocked, he said.
No explanation was provided for the shutdown of his accounts on the popular Sina Corp. platform, Weibo, and three other microblogging sites, Hao said. He said his Weibo account had about 4 million followers.
"The ruling party is losing in the field of public opinion, which is threatening its legitimacy," Hao said. "Now, they must exert tighter control, and that's why they have gone on the offense in public opinion."
The blog closure could have been related to Hao's recent post of a two-line verse critical of the party's authoritarian rule, or his posts criticizing the freezing of a microblog belonging to He Bing, an outspoken, liberal professor at the China University of Political Science and Law.
In a rare move, the official China Internet Network Information Center explained in state media reports Friday that He's account had been suspended because he was "intentionally spreading rumors."
The professor has issued a statement protesting the suspension as being illegal. "It is every citizen's responsibility to unswervingly promote a government that rules by law," He said.
The ratcheting up of controls on Chinese microblog platforms -- targeting verified accounts of well-known opinion leaders with hundreds of thousands of followers -- appears designed to send warnings that China's leaders will not give ground to its political critics, no matter how popular they might be.
President Xi Jinping has made fighting official corruption a priority, and the investigation against Liu had suggested that the government was willing to allow the public to play a role.
The investigation was foreshadowed by public allegations against him five months ago by Luo Changping, deputy chief editor of Caijing magazine. The official probe against Liu was announced Sunday, and on Tuesday state media reported that Liu has been removed from his posts as part of investigations into "serious disciplinary violations."