The USGS reported the earthquake striking just off the coast of the Alaskan Peninsula, near Sandpoint, Aleutians East, at 10.15pm on Wednesday local time (7.15am Thursday BST). The major tremor was reported at a depth of 46.7km, with a tsunami warning issued for as far away as Hawaii.
The US Tsunami Warning System said: “BASED ON ALL AVAILABLE DATA A TSUNAMI MAY HAVE BEEN GENERATED BY THIS EARTHQUAKE THAT COULD BE DESTRUCTIVE ON COASTAL AREAS EVEN FAR FROM THE EPICENTER.
“AN INVESTIGATION IS UNDERWAY TO DETERMINE IF THERE IS A TSUNAMI THREAT TO HAWAII.”
The agency said that, if tsunami waves impact Hawaii, the estimated earliest arrival time would be 12.53am local time on Thursday.
This is a breaking news story, more to follow.