Alaska earthquake prompts tsunami alert

A tsunami alert has been issued after a 7.9-magnitude earthquake was recorded off the coast of Alaska in the US.

It hit 280km (173 miles) south-east of Kodiak, at a depth of 25km, at 00:31 (09:31 GMT), the US Geological Survey said.

The US National Weather Service says a warning is in effect for the coasts of Alaska and British Columbia, while the US west coast is on tsunami watch.

But the tsunami watch for the islands of Hawaii and Guam has been cancelled.

Officials in Anchorage warned coastal areas, saying there was "extraordinary threat to life or property".

The alert told people to seek refuge on higher ground in affected areas. Residents in several places around the Gulf of Alaska were told to leave. They included Homer, Seward, Kodiak, Sitka and Unalaska, a source at Alaska Public Radio told the BBC.

According to Kodiak police, officials had reported water receding from the harbour.

The police said that "at this time the tsunami warning is still in effect. Remain at high ground".

"We have received two reports that the tide levels have been fluctuating in the channel six inches to one foot (15-30cm).

Many residents in Kodiak left by car in the middle of the night.

The NWS Pacific Tsunami Warning Center said that, based on the preliminary earthquake parameters, "widespread hazardous tsunami waves were possible".

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The alert meant that emergency officials and the public should prepare to take action.