No casualties have been reported so far in the strong tremor measuring 6.8 on the Richter scale that rocked Zhongba County, Xigaze Prefecture in Tibet on Monday, an inspection team leader Zhu Quan said on Saturday.

Zhu, the Tibet Seismological Bureau chief, said the team was continuing the assessment at the earthquake epicenter and found there is a big crack on the earth's crust.

"Some sections of the roads in the county are still blocked by mountain rocks that fell off in the earthquake, which impede the inspection team from entering six villages in the county," Zhu told Xinhua over phone.

Guo Chunming, an emergency disaster relief official with the team said that the strong jolt caused no big damages to the county, which is a sparsely-populated plateau pasturing place.

"We have checked 53 villages, where cracks were found on 700 houses. There are also some herdsmen living in tents here. None of them were injured," said Guo.

The regional observatory forecast rainy weather in the next few days, which dimmed the hope of reopening the disrupted road traffic to the six villages, he said.

The seismologists found a 10-km crack in north-south direction at the epicenter, which is at 31 degrees north and 83.6 degrees east.

Gerze and Coqen counties in Ali prefecture in Tibet also felt the quake.

The earthquake bureau chief said the tremor would have no effect on the Qinghai-Tibet railway, which is several hundred kilometers away from the quake zone.

Zhongba, in the west of Xigaze with a population of 18,000 and covering 43,594 square kilometers, is prone to quakes.

A 6.7-magnitude quake occurred in the area in 2004, followed by a 6.5-magnitude on April 8, 2005, but both caused no casualties, according to the regional earthquake bureau.

(Xinhua News Agency August 30, 2008)