Tsunami alert for Alaska and British Columbia after 7.9-magnitude earthquake

A tsunami alert for Alaska and British Columbia has been cancelled hours after being issued following a 7.9-magnitude earthquake.

Much of the US West Coast was also under tsunami watch after the earthquake struck 175 miles south east of Alaska's Kodiak Island on Tuesday.

Although tsunami warnings have been cancelled there remains a tsunami advisory in effect for southern Alaska according to the US National Weather Service's National Tsunami Warning Centre.

Warning messages from the National Weather Service urged people in Alaska to move inland or find high ground.

Text messages warned people on the island of tsunami danger along its coast after the earthquake which was initially reported as an 8.2-magnitude by the US Geological Survey.

The NWS Pacific Tsunami Warning Center initially said that, based on early estimates, "widespread hazardous tsunami waves were possible".

People in the affected area reported on Twitter being woken by the ground shaking and tsunami alert sirens sounding.

Residents as far as 300 miles north of Kodiak in Anchorage - Alaska's largest city - reported feeling strong shakes when the earthquake hit.

One woman shared video footage of a tsunami siren sounding in Kodiak shortly after 1am.

"Tsunami sirens going off in Kodiak after the earthquake, i usually only ever hear the weekly siren test at 2pm on wednesdays so hearing it at 1am on tuesday is actually terrifying!!" she wrote.

Kodiak Police Department advised residents to get "at least 100 feet" above sea level to ensure their safety.

There have been no reports of life-threatening waves or damage to property.