LHASA - Local authorities said no casualties or property damages have been reported after an earthquake measuring 5.1 on the Richter scale jolted Tibet at 3:40 am Tuesday.

The quake struck the sparsely-populated Nyima county of Nagqu prefecture in the northern part of Tibet, according to the China Earthquake Networks Center. The epicenter was at 33.9 degrees north latitude and 87.8 degrees east longitude.

The epicenter is in a "no man's land" and no tremor was felt in the county seat, a county government spokesman said.

Nyima county, covering about 70,000 square km and with an average altitude of more than 5,000 meters, has a population of 34,000.