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 USGS has issued a tsunami advisory for Amchitka Pass and Hinchinbrook Entrance, while a more urgent warning is in place for Samalga Pass. A tsunami watch is in place for Hawaii.

       Videos on social media showed tsunami warnings ringing out eerily in Alaska after the massive quake.

       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 epicentre.

       "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.

       The quake was registered 91 km east-southeast of Perryville, Alaska.

       The USGS shake map shows the tremors reaching far from the epicentre, with more than 250 people already reporting feeling it.

       An aftershock forecast has also been issued, with the USGS warning people to "be ready for more earthquakes."

       The warning said: "More earthquakes than usual - called aftershocks - will continue to occur near the mainshock.

       "When there are more earthquakes, the chance of a large earthquake is greater which means that the chance of damage is greater.

       "The USGS advises everyone to be aware of the possibility of aftershocks, especially when in or around vulnerable structures such as unreinforced masonry buildings.

       "This earthquake could be part of a sequence. An earthquake sequence may have larger and potentially damaging earthquakes in the future, so remember to: Drop, Cover, and Hold on."

       This is a breaking news story, more to follow.