China has confirmed that its troops opened fire on a group of Tibetans trying to cross into Nepal, leaving one of them dead.
The official Xinhua news agency quoted an official as saying the border guards fired in self-defence.
Earlier reports said two people were killed as nearly 70 people were attempting to illegally cross the Nangpa La pass on 30 September.
A Tibetan welfare group said 42 of the group had managed to enter Nepal.
Officials said the troops tried to "persuade them to go back home... but the stowaways refused and attacked the soldiers", Xinhua reports.
"Under the circumstances, the frontier soldiers were forced to defend themselves and injured two stowaways," the unnamed official was quoted.
'Dead in the snow'
The news agency report said one of the two injured died later in the hospital while the other was recovering, no other details about the victims were disclosed.
Earlier in the day a Chinese foreign ministry spokesman, Liu Jianchao, was quoted saying the matter "would be investigated" if it was found to be true.
On Wednesday a British climber, Steve Marsh, told the BBC of his shock when he saw Chinese border guards shooting dead a Tibetan refugee in a group trying to flee to Nepal.
The incident occurred as Mr Marsh was resting at a camp on the Tibetan side of the Himalayan peak of Cho-Oyu. He said scores of other mountaineers also witnessed it.
He said the soldiers fired twice but the group continued.
There was a third shot, the last in the group fell but was helped to move on a few yards, then there was a fourth shot which left the person dead in the snow.
Soon after the shooting, a group of young children were marched through Mr Marsh's camp by Chinese soldiers. Their fate is unknown.
Tibetan welfare organisations say they had been taken from the escaping group, more of whom moved on to Kathmandu, where the UN refugee agency has questioned them.
Correspondents say hundreds of Tibetans flee to Nepal every year but for years now Kathmandu, keen not to alienate Beijing, has passed new refugees onto India, where Tibet's exiled spiritual leader, the Dalai Lama, is based.