U.S. Secretary of State Hillary Clinton on Thursday called for an unfettered worldwide Internet and urged global condemnation of those who conduct cyber attacks, as China sought to contain tension with the United States over the hacking and censorship of Google.

"A new information curtain is descending across much of the world," she said, calling growing Internet curbs the modern equivalent of the Berlin Wall.

"We stand for a single Internet where all of humanity has equal access to knowledge and ideas," said Clinton in a major address that cited China, Iran, Saudi Arabia and Egypt among countries that censored the Internet or harassed bloggers.

Countries that built electronic barriers to parts of the Internet or filtered search engine results contravened the U.N.'s Universal Declaration on Human Rights, which guarantees freedom on information, she said.

Addressing concerns about cyber spying in China that have prompted Google Inc. to threaten to quit that market, Clinton said "countries or individuals that engage in cyber attacks should face consequences and international condemnation."

"In an interconnected world, an attack on one nation's networks can be an attack on all," Clinton said.

"We look to Chinese authorities to conduct a thorough investigation of the cyber intrusions that led Google to make this announcement," she said.

CHINA PLAYS DOWN ROW

In Beijing, comments by Chinese Vice Foreign Minister He Yafei on Thursday appeared to be part of an effort to play down disputes and avoid further straining ties with Washington that are already troubled by quarrels over trade, Taiwan and human rights.

"The Google incident should not be linked to bilateral relations, otherwise that would be over-interpreting it," the official Xinhua news agency quoted He as telling Chinese reporters.

He seemed to be seeking to limit potential fallout from the Google dispute, which could compound tensions with Washington as Congress heads into an election year and U.S. criticism of Chinese trade practices escalates.

Google, the world's top search engine, said it may shut its Chinese-language Google.cn website and offices in China after a cyber attack originating from China that also targeted others.

Google said it no longer wanted to censor its Chinese Google.cn site and wanted to talk with Beijing about offering a legal, unfiltered Chinese site. Searches for sensitive topics on Google.cn are still largely being censored.

Many in China see Google's ultimatum as a business tactic because its market share trails the popular Chinese search site Baidu, which is strictly censored. Despite extensive public debate of the Google issue in China, hacking has been rarely mentioned in official media.

Facebook, Twitter and YouTube are blocked in China.

A MIXED BLESSING

Clinton noted that text messages had helped rescuers in Haiti find a young girl and two women trapped in a supermarket after the earthquake and the U.S. text "HAITI" campaign that had raised more than $25 million from mobile phone users.

But she warned that Internet technologies were a mixed blessing because along with the benefits of spreading knowledge and empowering citizens, the web is used by al Qaeda to spread hatred and by authoritarian states to crush dissent.

"The same networks that help organize movements for freedom also enable al Qaeda to spew hatred and incite violence against the innocent," she said.

"And technologies with the potential to open up access to government and promote transparency can also be hijacked by governments to crush dissent and deny human rights," said Clinton.

China, Tunisia and Uzbekistan had stepped up censorship of the Internet, while Vietnam had cut access to popular social networking sites and Egypt had detained 30 bloggers and political activists, she said.

Saudi Arabia, China and Vietnam had also blocked Internet access to religious information or silenced people of faith, Clinton added.

The United States recognized limits to freedom of speech and the need to combat use of the Internet to spread hate speech, recruit terrorists or distribute stolen intellectual property.

"But these challenges must not become an excuse for governments to systematically violate the rights and privacy of those who use the Internet for peaceful political purposes," she said.

The United States was reinvigorating its Global Internet Freedom Task Force, Clinton said. She urged U.S. private firms to look beyond profits to play a "proactive role in challenging foreign governments' demands for censorship and surveillance."