The deadly 6.8-magnitude earthquake that jolted Dingri county of Shigatse in the Xizang autonomous region on Tuesday happened following a northward compression from the Indian Ocean plate and crustal movement, according to the China Earthquake Networks Center.

The quake's epicenter was located in the Lhasa block in southern part of the Qinghai-Tibet Plateau, the center stated. It happened because of extensional rupture and represented an energy release event within the Lhasa block, it said.

Since 1950, a total of 21 earthquakes above magnitude 6 have occurred in the Lhasa block, with a maximum magnitude of 6.9, it said.