BEIJING (AP) — A strong earthquake shook part of southwestern China on Monday afternoon. It wasn’t immediately clear if there was damage.

The 6.8-magnitude earthquake jolted Luding county in Sichuan province at 12:52 p.m., Xinhua news agency reported.

The 6.6 magnitude earthquake was centered at a depth of 10 kilometers (6 miles), according to the U.S. Geological Survey. Preliminary measurements by different agencies often differ slightly.

Shallower quakes tend to cause more damage.