MAINLING, Tibet - Two rescue teams were dispatched Sunday to the site of an avalanche that killed two people and trapped another four in the Yarlung Tsangpo River Canyon in west China's Tibet autonomous region, local authorities said Sunday.

The government of Meiling county in Nyingchi prefecture received a report at 5 pm Friday that an avalanche had killed two people and injured another two, a county government official said.

One of the two injured suffered a broken foot, while the other suffered a leg fracture. Both are trapped with two uninjured people in a remote area in the Yarlung Tsangpo River Canyon nature reserve, the official said.

Sun Huitao and Wei Feng, a pair of tourists from central China's Henan province, entered the canyon at 11 am on April 19 with five local residents of Meiling county without permission, the official said.

The avalanche happened at 3 pm on April 30. Sun, who had managed to escape the avalanche, made his way back to town and reported the incident on Friday.

The prefectural government commenced rescue efforts on Friday. An initial rescue team departed at 8 pm Friday and is expected to arrive at the scene four or five days later, as the rescuers need to climb eight mountains to reach the area where the climbers are trapped. A second team departed at 6 am Saturday and a third will leave at 12 am Monday, the official said.

Severe weather is limiting the use of electronic equipment and thus complicating the rescue, the official said.