A minor earthquake rattled the San Francisco Bay area.
The US Geological Survey's preliminary report put the quake at a 4.0-magnitude, last night. The temblor's epicentre was near Alamo, California, about 45 kilometres east of San Francisco.
There were no immediate reports of damage or injuries in Alamo or surrounding communities, said Contra Costa County Sheriff's spokesman Jimmy Lee.
The quake hit just after 9 pm and could be felt throughout the region.