Updated

At least seven people were killed during pro-independence demonstrations in an ethnic-Tibetan area of southwest China on Sunday, a Tibetan human rights group said, marking the latest reported upsurge of violence since the riots in Lhasa last week.

Tibet's spiritual leader the Dalai Lama also called for an international investigation into the crackdown against protesters in Tibet, which he said is facing a "cultural genocide."

In the Tibetan capital Lhasa, witnesses say large numbers of Chinese security forces have taken complete control of the city and its streets are largely deserted.

The Tibetan government in exile also said Sunday at least 80 people died in the Lhasa violence last Friday. China's state-run Xinhua News Agency has said only 10 "civilians" were killed.

The Tibetan Center for Human Rights and Democracy said Sunday two witnesses have told the organization that protestors died during clashes in the town of Aba in Sichuan Province.

The group, which is based in Dharmsala in India, said well over 1,000 people, mainly monks, have been taking part in the anti-government protests centered on the town's market square.

The London-based Free Tibet Campaign reported earlier Sunday that five people have been killed in violence in the town, according to witnesses.

The dead include four demonstrators and one soldier, the group said.

Reuters news agency reported that about 200 protestors in Aba hurled petrol bombs and burned down a police station, quoting an unnamed police officer.

The police woman reportedly said security personnel had fired tear gas to disperse the crowd, but there was no mention of casualties.

The Tibetan rights group told Kyodo News it was the second day of protests in the town.

Spokesman Tenzin Norgay said, "They are calling for independence and the return of the Dalai Lama. The protests are led by monks from a nearby monastery, but others are joining in."

Rights groups and Tibetan exile organizations have also reported other protests taking place in ethnic-Tibetan areas of western Gansu Province since the riots in Lhasa on Friday.

Government buildings are said to have been destroyed when several thousand demonstrators held a second day of protests in the town of Xiahe on Saturday.

The Free Tibet Campaign said a protest was also held in the town of Taktsang in Gansu on the same day, quoting witnesses, with protestors burning Chinese flags and shouting slogans calling for the return of the Dalai Lama from exile.

The Tibetan Center for Human Rights and Democracy separately said Sunday it has received reports of a demonstration at Rebkong County in Qinghai Province, where security forces are firing on crowds to disperse them.

There are large ethnic-Tibetan populations outside Tibet in the western Chinese provinces of Gansu, Qinghai, Sichuan and Yunnan.

Meanwhile, in Lhasa, the regional government says the city is "calm" but the authorities have released a statement saying they will "firmly counterattack" to restore stability.

A British journalist in Lhasa, James Miles, told Kyodo News that security forces carrying weapons now appear to control all areas of the city, including the old quarter of the capital where much of the looting and arson took place Friday.

"People are fearful of leaving their homes in case they get hit by a stray bullet," he said.

"There's also a general worry now about the deadline of Monday night for those involved in the rioting to give themselves up. People fear there will be house-to-house searches and arrests," he added.

One ethnic-Chinese tour operator, who only gave his surname Pan, said that all hotels and many businesses are closed and the streets are virtually deserted.

He said ethnic-Chinese are particularly scared as many were attacked and their businesses were looted and burned Friday.

"We are too scared to go out," he said.

Another Chinese tour operator, who gave his surname as Zhang, confirmed that tourists have been barred from coming to Lhasa and the city is effectively sealed off by the military.

Lhasa Mayor Doje Cezhug told the state-run Xinhua News Agency that security in Tibet has improved and that only a handful of people were behind the violence. Xinhua has also carried reports of traffic returning to "normal" in parts of the city.

"The situation in Tibet as a whole is good at the moment. The government is able to maintain stability for the people," the mayor said.

Speaking to reporters in Dharmsala on Sunday, the Dalai Lama said there should be an investigation into whether cultural genocide, intentional or not, was taking place in Tibet.

"Some respected international organization can find out what the situation is in Tibet and what is the cause," he said.

"Whether the (Chinese) government there admits or not, there is a problem. There is an ancient cultural heritage that is facing serious danger," he said. "Whether intentionally or unintentionally, some kind of cultural genocide is taking place."

Referring to the violent turn of the protests in Tibet, the Dalai Lama said he is totally committed to non-violence and that Tibetans in Tibet also believe in that. He appealed to the protesters to shun violence and make peaceful protests.

He also said the international community had the "moral responsibility" to remind China to be a good host for the Olympic Games, while adding that the Games in Beijing should not be called off.