"What happened in Lhasa is a law and order issue and no government would tolerate looting, burning, killing. And any responsible government needs to do something about it," Zhou told reporters on Tuesday.
Rejecting allegations of repressive rule in the Himalayan region he said Tibet's religious freedom had "developed tremendously" under China's administration, he said.
Zhou's attempt to calm international concern comes as China seeks to head off concerns that its actions in Tibet may impact on Beijing's hosting of the Olympics in August.
On Tuesday the Tibet issue entered the US presidential campaign, with Hillary Clinton calling for increased US pressure on China.
"I think that what's happening in Tibet is deeply troubling, and this is a pattern of the Chinese government with respect to their treatment of Tibet," the Democratic candidate said.
|Protesters are calling for greater |
diplomatic pressure on China [EPA]
"I don't think we should wait until the Olympics to make sure that our views are known," Clinton said while campaigning in Pennsylvania.
Chinese leaders are scrambling to prevent international anger over Tibet taking the lustre off the Beijing Olympics – an event they see as symbolic of China's rise as a responsible global power.
Critics have vowed to use China's hosting of the games and the international spotlight it will bring to stage protests against Chinese rule in Tibet and over China's human rights record in general.
On Monday three activists from Reporters without Frontiers, a press freedom group, were detained when they attempted to disrupt the start of the Olympic torch relay in Greece.
To date calls for an Olympic boycott have gained little support among world leaders, but on Tuesday Nicolas Sarkozy, the French president, hinted that he may consider a boycott depending on the course of events.
|Sarkozy said he has not dismissed|
the possibility of a boycott [AFP]
"All options are open but I appeal to the sense of responsibility of Chinese authorities," he said.
"I have expressed to [Chinese] President Hu Jintao my strong concern and asked him to show a sense of responsibility and the opening of dialogue."
Later Sarkozy's aides told reporters that while a boycott of the opening ceremony was possible, France would not boycott the entire games.
Other countries have spoken out against calls for a boycott saying it would have no impact on the situation in Tibet.
"A wrecked Olympics is actually not going to to anything for human rights in China," David Miliband, the UK foreign secretary, said on Tuesday while presenting Britain's latest annual report on world human rights.
Nonetheless diplomatic pressure is intensifying on China to show restraint in handling the demonstrations.
Call for dialogue
At a meeting of the UN Human Rights Council in Geneva the European Union, US and other Western nations again called on China to stop using force against Tibetan protesters.
They also urged China to engage in dialogue with Tibetan representatives.
Tibetan exiles say more than 100 have died in
the Chinese crackdown [AFP]
China says there have been 20 deaths in the unrest over the past two weeks, while Tibet's government in exile in India said 140 people have been killed.
The protests began in Lhasa on March 10 on the 49th anniversary of a failed uprising against Chinese rule, and subsequently spread to surrounding regions.
China's state-run Xinhua news agency reported earlier this week that a police officer was killed during a protest in Garze prefecture in Sichuan province, home to a large number of ethnic Tibetans.
Clashes between authorities and rioters armed with knives and stones in the western Chinese province also reportedly injured "several others", the agency said.
Citing sources in Garze, the Tibet Support Group - a human rights body founded by exiled Tibetans - said that a monk and a farmer were also killed in the unrest.
It is difficult to gain any independent verification of these or other reports from the region.
Despite Beijing's promise to introduce greater media openness in the lead up to the Olympic games, Tibet has remained strictly out of bounds for foreign journalists.
At the UN human rights meeting in Geneva on Tuesday, Warren Tichenor, US ambassador to the UN, said China's refusal to allow foreign media access to the region ran "counter to China's Olympic bid commitments".