BEIJING, China – China braced against further protests on Sunday as it prepared for the arrival of the Olympic torch amid reports of fresh disturbances in the riot-torn Tibetan capital Lhasa.

Beijing tightened security in Tiananmen Square, where the Olympic torch will be officially welcomed to the country on Monday before beginning a worldwide relay expected to be dogged by protests over the unrest in Tibet.

Tension in the Himalayan region continued to simmer, according to the Tibetan government-in-exile and activist groups, which reported a protest in Lhasa on Saturday.

The disturbance occurred when hundreds of residents of the city's Tibetan quarter panicked as police moved in to check identity papers of people there, according to the International Campaign for Tibet and the Free Tibet Campaign, citing their own sources.

The incident prompted police to surround key Buddhist temples in the area and close many shops, said the accounts, which added no reports of violence were received.

Local authorities corroborated the incident in a text message to phone subscribers which said the security checks caused "frightened citizens" to flee, according to the activist groups.

"Please obey the law and please follow the rules," it pleaded. "Don't create rumours, don't believe rumors."

Demonstrations in Lhasa on March 10 to mark a failed 1959 uprising against Chinese rule escalated into widespread rioting in the city that spread to neighbouring Chinese provinces populated by Tibetans.

Beijing says rioters killed 18 civilians and two police officers. Exiled Tibetan leaders have put the death toll from the Chinese crackdown at 135-140 Tibetans, with another 1,000 injured and many detained.

China has since come under heavy foreign pressure to open a dialogue with the Dalai Lama on Tibet's future.

But a commentary by the official Xinhua news agency Sunday rejected the suggestion, accusing the exiled Tibetan spiritual leader of having "closed the door of dialogue."

China tightened security Sunday around the already closely watched Tiananmen Square, site of the 1989 democracy protests that were crushed by the government.

Authorities announced new spot checks on visitors to "strengthen public security", according to a government website, ahead of Monday's torch-welcoming ceremony.

The torch is set to depart China on Tuesday for a four-month relay around the world and throughout China.

Fears of global embarrassment for China along the route have grown since protesters disrupted the lighting ceremony in Ancient Olympia last Monday.

With Greece set to hand over the flame to China in Athens, Greek authorities were taking no chances.

In a possible preview of relay route security elsewhere, 2,000 officers patrolled Athens as sporadic protests by pro-Tibetan activists and Greek leftists rose.

In the latest signs of anti-Chinese anger, exiled Tibetans in India on Sunday lit an "independence torch" that will also be taken around the world.

Meanwhile, police in Nepal's capital Kathmandu baton-charged protesters -- most of them Tibetans -- during a demonstration outside a Chinese embassy office, detaining more than 100, police and witnesses said.

In Taipei, more than 100 Taiwanese and Tibetans demonstrated Sunday, chanting, "Who is the killer? Hu Jintao!" "Shame!" "Shame!", referring to China's president.

China, however, continued its much-criticised crackdown on the Tibetan unrest, with Xinhua reporting late Saturday that police arrested 26 people and seized guns and other weapons from a monastery whose monks rioted on March 16.

It did not specify whether those arrested Friday were monks from the Geereng monastery, also known as Kirti, in the southwestern province of Sichuan, which borders Tibet.

Activist groups have said eight people were killed in the Geereng clashes, while China says police merely shot and wounded four rioters.

China has ruled Tibet since 1951, a year after sending troops in to "liberate" the region from what it said was feudal rule.