Two earthquakes have shaken the Puget Sound region in America's Washington state, with the tremors felt into British Columbia and across the Cascade Mountains into the eastern part of the state.
There were no immediate reports of damage or injuries.
The US Geological Survey reports that a 4.6 magnitude earthquake rattled the Three Lakes area, about 64 kilometres northeast of Seattle. That was followed minutes later by a 3.5 magnitude aftershock near the city of Monroe, about 48km northeast of Seattle.
The initial jolt was recorded at 2.51am local time on Friday.
The state Department of Transportation said the agency would be inspecting bridges, but had no reports of damage.
The USGS said it received reports of people feeling the shaking from Vancouver to near Wenatchee, Washington.
Further south along the Pacific coast, a magnitude 4.9 aftershock of last week's Southern California earthquakes was felt widely in the region on Friday morning.
There have been thousands of aftershocks of the magnitude 6.4 earthquake on July 4 and the 7.1 quake that occurred the next day.
David Caruso, a USGS geophysicist, told The Seattle Times the Washington state quake was due to a thrust fault, in which one side of a fault pushed upward relative to its opposite side. Such quakes are common in the Cascade Mountain range.
Caruso said the Northwest quake had no connection to the recent earthquakes in California.
© AAP 2019