A 7.7 magnitude earthquake that hit the west coast of Canada has sparked a tsunami warning for Hawaii, thousands of miles to the west.
Emergency sirens sounded late on Saturday to alert residents around the islands that make up Hawaii.
Wave heights of one to two metres were predicted in some areas, as "urgent action" was advised to protect lives.
There were no immediate reports of damage on the Canadian coast following the earthquake.
The BBC reports that tsunami alerts that were issued for coastal areas of Alaska and British Columbia were swiftly downgraded.
The quake hit 200 kilometres south-west of the Canadian mining town of Prince Rupert at a depth of 18km, said the US Geological Survey.
Initially, the Pacific Tsunami Warning Center said it did not expect a threat beyond the immediate area.
But later it said: "A tsunami has been generated that could cause damage along the coastline of all islands in the state of Hawaii."
It said the first tsunami wave could hit the archipelago by about 22.30 local time.
"Urgent action should be taken to protect lives and property," the warning said.
Hawaii is made up of hundreds of islands and people living in areas considered to be at risk were being urged to move to higher ground.
The quake struck the coast of western Canada at around 03:00 GMT and was followed by a 5.8 magnitude aftershock.
People in coastal areas of Canada's Haida Gwaii archipelago - formerly known as the Queen Charlotte Islands - were reportedly being moved to higher ground as a precaution.
Following the quake, small waves measuring 69 centimetres were reported on the north-east tip of Haida Gwaii, while parts of the north-east coast of Vancouver Island saw waves up to 55cm high.
Civil Defence in New Zealand says people in New Zealand need not be concerned for their safety following the earthquake and tsunami.