Xinhua said in the early hours of Saturday public order had "basically returned to normal", but added some people had been taken to hospital with injuries. It did not say who they were.
"The problem is that a lot of injured Tibetans may end up in prison, where the medical care is really poor," said John Ackerly, president of the International Campaign for Tibet, in Washington.
A spokesman for the Dalai Lama, contacted in the Indian town of Dharamsala, a centre for Tibetan exiles, said of the Chinese allegation against "the Dalai clique": "This is absolutely baseless and his holiness has made his stand very clear."
The Dalai Lama has in recent years called for limited autonomy for Tibet, but some Tibetans demand full independence.
The protests present hard choices for President Hu Jintao, who was Communist Party boss in Tibet in 1989 when China imposed martial law to quell anti-Chinese protests.
U.S. URGES RESTRAINT
U.S. ambassador to Beijing Clark Randt told senior Chinese officials of Washington's concern.
"He took the opportunity, because of what was going on in Lhasa, to urge restraint on the part of the Chinese officials and Chinese security forces," a U.S. spokesman told reporters.
U.N. High Commissioner for Human Rights Louise Arbour urged China "to allow demonstrators to exercise their right to freedom of expression and assembly, to refrain from any excessive use of force while maintaining order and to ensure that those arrested are not ill-treated".
Police in New York said they arrested six pro-Tibet protesters who tried to enter U.N. headquarters.
The devoutly Buddhist people of Tibet's vast plateau have won international sympathy, but little international recognition of claims to sovereignty, since Chinese troops invaded in 1950.
Nine years later came the failed uprising and the flight of the Dalai Lama and thousands of his supporters into exile.
A Han (majority) Chinese resident of Lhasa said the protests were being directed at the city's Han Chinese population, which has mushroomed in recent years with China's economic boom. "The Han Chinese are really scared," he said.
Many Han Chinese immigrants are small shopkeepers and traders. Xinhua said some shops were set on fire on Friday.
"At one o'clock, Friday afternoon Lhasa time, people were ordered to stay in their offices, stay in their schools, and if they were at home, to stay at home," said Ben Carrdus of the International Campaign for Tibet.
The demonstrations in Lhasa spilled over into at least one other ethnic Tibetan area of China.
Hundreds of monks of Labrang monastery in the northwestern province of Gansu led a march through the town of Xiahe, the Free Tibet Campaign said, citing sources in Dharamsala, home to Tibet's government-in-exile.
About a dozen Tibetan exiles in India were arrested when they tried to storm the Chinese embassy in New Delhi on Friday.
