BEIJING, OCT. 3 (SATURDAY) -- Tibetan demonstrators calling for independence from China burned a police station and several police cars in Lhasa Thursday. Six persons were killed in the riot, the official New China News Agency said early today.

Travelers from Lhasa arriving in the city of Chengdu yesterday said they heard unconfirmed reports that eight had died in the violence, which erupted on China's national day.

The news agency blamed the demonstrators, saying some had grabbed guns from policemen and fired at the police and crowds. It said the police did not fire on demonstrators, but tourists said that most, if not all, of those killed were Tibetans rather than Chinese policemen.

The news agency did not identify the six persons who were killed but said that 19 policemen were seriously injured in the rioting, in which a police station was burned down.

The agency published a commentary from the official People's Daily that blamed the exiled Tibetan Buddhist leader, the Dalai Lama, who recently visited the United States. The article called the violence "a serious political incident instigated and engineered by the Dalai clique."

A Chinese official reached by telephone in Lhasa today denied the tourists' reports that police had detained a number of tourists, confiscating their film. But CBS News reported that two Americans were arrested during a demonstration Sunday led by Buddhist monks.

A traveler from Lhasa identified the two as John Ackerly of Cambridge, Mass., and Blake Kerr of East Hampton, N.Y.

Telephone and post office employes in Beijing said Chinese authorities had cut telephone and telex communications with Lhasa temporarily, apparently in an attempt to keep the embarrassing news of unrest in Tibet from reaching the outside world.

Nothing like Thursday's demonstration has been openly reported since 1959, when the Chinese suppressed a major uprising, causing more than 100,000 Tibetans to flee to neighboring India.

Among them was the Dalai Lama.

The tourists said Tibetan youths had hurled stones at police. "I saw a man bleeding to death on the ground . . . . We heard a lot of gunfire," one tourist told Agence France-Presse.

Chengdu, located 780 miles east of Lhasa, is the main jumping-off place for tourists traveling by air to Tibet.

Leon Schadeberg, a free-lance photographer from London, told The Associated Press in Chengdu that Thursday's violence erupted after eight monks began protesting the arrest of 21 of their fellow clergymen on Sunday.

He said the demonstrators set a police station and at least four police vehicles on fire and smashed the police station door. Witnesses said an undetermined number of detained monks escaped from the burning police station.

The violence comes at a sensitive time for China, which celebrated the 38th anniversary of the founding of the People's Republic of China on Thursday. The 36th anniversary of the Chinese Army's entry into Tibet is Oct. 7, and could spawn additional protests, according to some observers.

A visit by the Dalai Lama to the United States coincided with Sunday's demonstration in Lhasa. While in the United States, the Dalai Lama presented a five-point peace plan calling for the withdrawal of Chinese troops and a negotiated settlement of Tibet's status.

The commentary in the People's Daily, quoted by Reuters, said "Dalai is openly trumpeting for the independence of Tibet in the United States and other countries and he will never succeed in his separatist activities by courting the support of foreigners." Foreign diplomats here said that Chinese officials are certain to see a link between the Dalai Lama's visit and the protests.

A western diplomat said it was clear that the demonstrators felt emboldened by the attention the Dalai Lama received from U.S. congressmen and from supporters in the United States.