Three earthquakes have struck the Hunter Valley wine region in a three-hour period, with tremors felt as far away as Sydney.

A 3.8 magnitude earthquake hit Muswellbrook, in the Upper Hunter region, at 3.27pm on Monday.

The three earthquakes that struck the Hunter region in Denman and Muswellbrook were felt as far away as Orange and Sydney. Credit:Geoscience Australia

The quake occurred at a depth of 10km, according to Geoscience Australia.

About an hour later the town of Denman, which lies a 30-minute drive south-west of Muswellbrook, was rocked by a 4.4 magnitude quake.