SEOUL — The Nobel Peace Prize committee presented its award Friday in Norway to an empty chair reserved for imprisoned Chinese dissident Liu Xiaobo, a tribute that has both sharply focused Western criticism of China’s lack of human rights and unleashed a government crackdown by Beijing on the country’s small group of political activists.

In his keynote address in Oslo, committee chairman Thorbjorn Jagland not only called for Liu’s release, but also made clear the award was meant to warn of the perils of China’s growth as an economic superpower without the parallel development of its civil and legal institutions.

“We can, to a certain degree, say that China, with its 1.3 billion people, is carrying mankind’s fate on its shoulders,” Jagland said. “If the country proves capable of developing a social market economy with full civil rights, this will have a huge favorable impact on the world. If not, there is a danger of social and economic crises arising in the country, with negative consequences for us all.”

Liu had been taken into custody in December 2008 for his role in drafting a political manifesto known as Charter 08 that called for greater political freedoms in China, many of which are guaranteed by the nation’s own constitution. Then last December, the 54-year-old former literature professor was given an 11-year prison sentence for attempting to subvert the state.

The Nobel ceremony on Friday, which began with trumpeters heralding the king and queen of Norway, was a very long way from the prison cell in northeast China that Liu is said to now share with five other inmates.

“It indicates the current situation of China, only an empty chair can represent the situation in China,” said Pu Zhiqiang, a leading Beijing human rights lawyer who said he’s followed by police everywhere he goes.

During the nine weeks after the Nobel committee announced that Liu was being recognized, Chinese officials pushed a propaganda campaign to brand Liu a “criminal,” asked other nations to boycott the ceremony in Oslo, and put dozens of Chinese activists under house arrest.

The campaign to harass dissidents in China hit a fever pitch in recent days with some 300 people detained, put under surveillance or told to temporarily leave Beijing, according to figures compiled by Human Rights Watch.

“This is really a high point (of such activity) in recent history,” said Nicholas Bequelin, a Hong Kong-based researcher for Human Rights Watch’s Asia division. For instance, one of the co-drafters of Charter 08, Zhang Zuhua, is said to have been shoved into a minibus and abducted in broad daylight in Beijing on Thursday afternoon, presumably by plainclothes police.

Chinese leaders ensured that no one would be present to accept the committee’s gold medal and check worth some $1.5 million by keeping Liu’s wife under house arrest. They also forbade any other members of Liu’s extended family, and in some cases just like-minded individuals, from leaving China.

After his speech, Jagland simply placed the Nobel medal and commendation on an empty blue chair.

It was the first time that neither the winner nor a representative was able to claim the prize since 1936 when Nazi Germany prevented pacifist Carl von Ossietzky from attending.

In Washington, the White House released a statement by President Barack Obama, last year’s winner, saying that, “Mr. Liu Xiaobo is far more deserving of this award than I was.”

“Mr. Liu reminds us that human dignity also depends upon the advance of democracy, open society, and the rule of law,” Obama said. “The values he espouses are universal, his struggle is peaceful, and he should be released as soon as possible.”

China’s attempts to convince other nations to not attend this year were partially successful, with some 16 ambassadors declining to show. Among those said to have avoided the event were Russia, Egypt, Pakistan and Cuba — all nations with terrible human rights records and considerable interest in gaining favor with the Chinese government.

In Beijing, both CNN and BBC were blocked off and on throughout the day, and for the entire broadcast of the ceremony. Police kept reporters from approaching Liu Xia’s apartment.

Xinhua, the state newswire, issued an article on Friday evening declaring that “China voiced strong opposition to this year’s Nobel Peace Prize Friday, saying the country is firmly against attempts to use the prize to interfere in its internal affairs.”

On Tuesday, Chinese Foreign Ministry spokeswoman Jiang Yu had told reporters “I would like to say to those at the Nobel committee, they are orchestrating an anti-China farce by themselves.”

She added: “We are not changing because of interference by a few clowns and we will not change our path.”

Those dissidents still able to answer the phone on Friday said the empty chair in Oslo was a haunting symbol of life in today’s China, where a wide array of security services can make those who speak out against the government, especially the Communist Party, simply disappear.

“The government’s understanding of universal values is far from what they actually are,” said Li Fangping, a rights lawyer who said he’d been escorted by police to the Beijing airport before flying to an undisclosed province and told not to discuss the Nobel Prize.

Pu, the human rights attorney in Beijing, said he’d been called to a meeting this week to receive a straightforward message: “State security told me that I should not talk too much on the 9th, 10th and 11th.”

Wu Wei, an activist in the southern city of Guangzhou, also said he had “just come back from tea” — a euphemism for often threatening conversations with security officers.

“The state security in Guangzhou warned me that I should not participate in any activities today,” said Wu, who like Liu Xiaobo is a member of the Independent Chinese PEN Center, a chapter of the free-speech advocacy PEN organization.

Bequelin, the Human Rights Watch analyst, said that beyond the anecdotal accounts of dissidents having a tough time in China, the broader picture is deeply troubling.

He described expectations by the West during the past two decades that economic engagement with China would result in governmental and societal reform.

“This has proven to be brutally wrong,” Bequelin said. “What we have is a China that’s far more powerful and has more reach around the world, but has not shed any of its autocratic ways.”