The snowfall buried tents and reduced visibility. The local authorities said that they were in contact with the hikers and that rescue efforts were underway.

A museum’s directors said Chinese and Thai officials pressured them to remove the names of artists whose works criticized China. The curator flew to London, fearing arrest.

A power struggle is taking shape over choosing a successor to the 90-year-old Buddhist leader. In a trip to Tibet’s capital, China’s leader emphasized maintaining Beijing’s control.