BEIJING -- Aftershocks, with the strongest measuring 5.1 magnitude so far, have kept striking the Qamdo prefecture, Tibet autonomous region on Monday.

No casualties have been reported from the quake-hit area.

A 6.1 magnitude quake jolted the border region of Zogang county and Markam county at Qamdo prefecture at 5:23 am Monday Beijing Time, according to the China Earthquake Networks Center.

The epicenter, with a depth of 10 km, was monitored at 30 degrees north latitude and 98 degrees east longitude, the center said.