A moderate earthquake struck a remote area of northern California on Wednesday morning, with no immediate reports of major damage or injuries.

The quake, which had a preliminary magnitude of 5.6, was centred about 140 miles (225 kilometres) northeast of San Francisco, according to the US Geological Survey.

Residents felt the earthquake across a wide area, including the fishing town of Fort Bragg.

The epicentre was about 50 miles (80 kilometres) east of Fort Bragg at 8:10 a.m. local time, and the US Geological Survey said the quake was centred at a depth of about 5 miles (8 kilometres).

A second earthquake of magnitude 2.5 struck near the epicentre minutes later.