San Francisco earthquake: Residents shaken awake in the early hours by magnitude 4.4 quake

Residents in the San Francisco Bay Area were shaken from their slumber by a magnitude 4.4 earthquake.

The quake struck in the early hours around 2 miles (3 kilometres) from Berkeley, according to the US Geological Survey.

It was felt over a wide area, with many people tweeting that they had felt the tremors on Thursday.

There was no major damage caused after the quake hit at 2.39am local time (10.39 GMT).

The epicentre of the earthquake was just across the bay from San Francisco, at a depth of 8 miles (13 kilometres).

While initial reports suggested a magnitude of 4.7, this was quickly downgraded.

Many people tweeted that they had felt the tremor, with posts showing some were disturbed up to 40 miles (64 kilometres) north and south of the site, the Associated Press reported.

The Mayor of Berkeley warned residents to be wary of aftershocks.

Local rail company Bay Area Rapid Transit reported no damage on lines and early delays in service were clear by 5.30am, the agency said.

Jack Boatwright, a geophysicist with the USGS Earthquake Science Center in Menlo Park, said the shaking from the quake "seemed a little weak, about half as strong as what you would expect."

He told the Chronicle that by 4.15am, there had been no aftershocks, which he called "a good sign. It may mean less likelihood of a larger earthquake to follow."