Oklahoma rocked by 5.6 earthquake Saturday morning: USGS
A technician of the French National Seism Survey Institute (RENASS) presents a graph of an earthquake. (AFP)

An earthquake of magnitude 5.6 hit the U.S. state of Oklahoma on Saturday, the United States Geological Survey reported.

It said the quake struck 15 km (10 miles) northwest of Pawnee in the north of the state and was 6.6 km deep.

There were no immediate reports of any damage or casualties.

(Writing by Gareth Jones)