The mainland's foreign ministry announced the death of a second victim, a 23-year-old male, days later in a hospital, stating that he had died from an 'oxygen shortage'. Human rights groups reject the claim and say he died from gunshot wounds sustained on the day of the shooting. The incident was caught on videotape and still cameras by western tourists.

Beijing has since claimed its border guards clashed with people attempting to leave the country illegally and were forced to fire in self defence.

Tenzin Norgay, a spokesman for the Tibetan Centre for Human Rights and Democracy, which is based in the northern Indian city of Dharamsala, said: 'This has been going on for a long time and we have been talking about this for a long time. But today China cannot escape it. The bubble that they created has burst.'

The plight of the 41 rural Tibetan refugees brings to light the hardships suffered by the estimated 2,500 to 4,000 Tibetans who try to reach India every year via Nepal, paying smugglers to bring them to India because obtaining the necessary travel permits and a passport are almost impossible.

In India they can speak about Tibetan culture and autonomy, which is a dangerous affair inside China. But their first priority is, almost universally, gaining an audience with the spiritual leader of Tibetan Buddhism, the Dalai Lama, whose residence, along with that of Tibet's government-in-exile, is in Dharamsala.

'Our aim only is to get the blessing of His Holiness the Dalai Lama,' said Tenzin Wangmo, a 24-year-old nun, explaining why she embarked on the journey. 'We were planning to go back afterwards but now it won't be possible after the trouble in the pass. If we go back to Tibet the Chinese will definitely arrest us.'

Namtso, the nun killed by Chinese patrolmen was typical of the many Tibetan refugees who make the journey: she was poor, young and motivated by religious yearnings. The small farming village she came from had about 40 homes and like her friend Dolma, with whom she set out for Dharamsala, she had never been to school.

'We were best friends,' said Dolma, who was separated from Namtso at the time of the shooting and only heard of her death many days later. 'Still, I cannot believe it,' she said, wiping away tears. 'I've lost everything.' Namtso was the only daughter among seven children and had become a nun the year before.

The two friends had been planning the journey for the past four years. Dolma said she left Tibet with 10,800 yuan, about half of which was for the smuggler. Now she has about a thousand rupees (HK$172) to her name. Most of the refugees paid the two smugglers 5,000 yuan - a fortune in poverty-stricken Tibet - to be brought safely to Nepal.

On September 30, walking in single file directly behind the nun who would be slain were three other nuns who began the journey together from the same village, setting off for Lhasa. The women described how, after a two-day truck ride from the Tibetan capital, the group was forced to hide on the side of a mountain and wait until nightfall to begin their journey. At the time there were 77 of them, including the two smugglers, and for the next 17 days the group walked mostly at night and slept during the day, braving high winds and chest-deep snow.

'For the last three days we had no food,' said Thupten Tsering, 36, a monk who is seeking religious freedom in India. He said that monks in Tibet were expected to denounce the Dalai Lama and swear their allegiance to China. 'The guides kept saying it would be one or two days more.' The three nuns said that they too had run out of the barley, butter and cheese they had brought from Lhasa.

Reaching the Nangpa La Pass early in the morning on September 30, the three nuns had been walking a few hours when they began to hear shooting. They said they never saw the Chinese patrolmen, but only heard the sounds of their guns.

'They were shooting all around,' said Venerable Wangmo. She said the bullets made a zinging sound as they passed by her ears.

'When the shooting was going on I just prayed to His Holiness the Dalai Lama to save us,' she said.

When a bullet hit Namtso she collapsed, blood coming out of her left side onto the snow. She cried out that she had been hit and asked for help, but the nuns around her were weak with cold, fatigue and hunger. Venerable Wangmo said she made an attempt to grab the wounded woman's arm and to pull her along, but she was too heavy. 'There was a monk from the group who said, 'She is dead - if we don't run away we will all be finished',' she said.

They were in chest-deep snow at the time, and getting through the pass was a gruelling challenge. When the shooting started they dropped all their supplies - a sleeping mat and what little extra clothing they had carried on their backs - ran towards the peak and over the top, continuing until evening. That night, without food and blankets, they huddled together for warmth.

The next day they walked until they encountered a small group of nomads with three tents who agreed to sell them provisions. From there they met up with other members of the group, with whom they walked for five more days, eventually taking a bus one final day to reach the Tibetan reception centre in Kathmandu, which like its counterparts in India, provides free food, lodging and transport to Tibetan refugees.

As with all Tibetan refugees who arrive in Nepal, the group had to wait a few weeks for paperwork from the UN's refugee agency and from the Indian embassy to be processed. There are 120,120 Tibetan refugees living in India, Nepal and Bhutan, according to Tibet's government-in-exile in Dharamsala.

At least half of those making the perilous journey from Tibet are children, sent by parents who want their children to grow up with a strong Tibetan identity and who often cannot afford school fees at home. Among the group of 41 Tibetans arriving in India who had accompanied the slain nun, the youngest was a seven-year-old girl, Deki Pantso, who came without her parents.

Most Tibetan refugees prefer to make the journey in winter, when there is deep snow in the high passes between Nepal and Tibet and the chances of being caught by Chinese patrolmen are greatly diminished.

The International Campaign for Tibet, a Washington-based advocacy group, estimated that 80 per cent of refugees attempt to cross between October and April, when the mountain glaciers are frozen over. Another reason is that the weather in parts of India can soar above 40 degrees Celsius in summer, temperatures Tibetans are unaccustomed to.

Rights groups say that it is impossible to know how many refugees die along the way each year, but they say a significant number fall into crevasses, die of hunger or are caught up in incidents such as the shooting.

But the plight of refugees fleeing over the border has never been so graphically documented. A Romanian cameraman and other western tourists who were in the region to climb Cho Oyu, one of the world's tallest peaks, about 20km west of Mount Everest, saw the Chinese patrolmen shoot the Tibetan refugees 'like dogs', as one tourist put it.

The incident grew in magnitude after the official mainland news agency, Xinhua, said the soldiers fired after the refugees attacked them.

The US and the European Union, which held an EU-China dialogue on human rights in Beijing late last month, have each condemned the shooting. But so far it is Canada that has delivered the harshest rebuke, when on October 18 Canada's Foreign Minister Peter MacKay expressed his 'abhorrence and dismay for this terrible incident that happened at the border', adding that 'Canada strongly condemns this act of violence against unarmed civilians as an egregious violation of human rights'.

Mr Norgay of the Tibetan Centre wondered whether this would lead to different governments pressuring China to improve its human rights record. 'I fear it might be another event come and gone. Public memory is very short.'