China tightens grip on Tibet amid threat to Olympic torch

China tightened its grip on Tibet today as it insisted the unrest there would not stop the Olympic torch from being taken to the top of Mount Everest.

Anti-government riots last week in the Tibetan capital Lhasa and a crackdown by communist authorities have led to calls from activist groups to stop the relay from going through the region via the mountain's summit before this summer's games.