Two recent earthquakes in southwest China's Tibet Autonomous Region did no damage to the world's highest railway, which is more than 1,000 kilometers from the epicenters, the local government has said.

An earthquake measuring 6.1 on the Richter scale shook border areas between Rutog and Gerze in Ngari Prefecture in western Tibet on Saturday afternoon.

On Monday, a quake measuring 5.6 jolted Tuoba Township in Qamdo Prefecture in the east.

No casualties have so far been reported because the quake-hit areas are remote, sparsely populated areas with relatively poor communications.

Experts with the regional meteorological bureau said the quake-hit areas were too far away to pose any threat to the Qinghai-Tibet Railway, the world's most elevated plateau railway that became operational last July.

But Monday's quake was likely to affect traffic on an interprovincial highway linking Tibet to neighboring Sichuan province, said Zhu Quan, head of the bureau.

"Investigators are still assessing damage to the Sichuan-Tibet Highway, whose northern section crosses the quake-hit area," said Zhu.

Though this part of the highway is not as busy as the southern section, Zhu said many tourists and adventurers prefer the seclusion and quietness of this route. "They need to be careful because landslides and falling rocks are a real possibility."

The regional government has sent investigators to assess damage and the meteorological bureau is closely monitoring aftershocks.

Tibet is one of the most earthquake-prone areas in China. Since records began in 1900, the region has on average suffered one to three strong quakes a year measuring over 6 on the Richter scale and another six measuring between 5 and 6.

In one of the world's strongest recorded earthquakes which hit Zayu County in southwestern Tibet in 1950, thousands of people died.

(Xinhua News Agency May 9, 2007)