This image made from the video posted to social media by Jared Griffin shows vehicles around Kodiak High School following the earthquake early on Sunday. AP

The US Tsunami Warning System withdrew a warning it had issued for coastal areas of South Alaska and the Alaska Peninsula.

USGS revised the magnitude of the earthquake down from an initial reading of 7.4, and it revised the depth of the quake to 32.6km from an initial 9.3 km.

There were no immediate reports of damage or casualties although a few Twitter accounts posted videos of tsunami sirens and strong tremors being felt.

The earthquake was felt widely throughout the Aleutian Islands, the Alaskan Peninsula and Cook Inlet regions, according to the Alaska Earthquake Centre.

In Kodiak, Alaska, sirens warned of a possible tsunami and sent people driving to shelters late at night, according to video posted to social media.

The United States Geological Survey wrote in a social media post that the earthquake occurred 106 kilometres south of Sand Point, Alaska, at 10:48pm on Saturday.

Before the cancellation, the National Weather Service in Anchorage, Alaska, tweeted that the tsunami advisory applied to coastal Alaska from Chignik Bay to Unimak Pass, but Kodiak Island and the Kenai Peninsula were not expected to be impacted.

The Hawaii Emergency Management Agency said shortly after the tsunami warning went out that there was no threat to the islands.

There were an estimated eight aftershocks in the same area of Alaska, including one measuring 5.0 magnitude within three minutes of the original earthquake, KTUU-TV reported. Residents were advised not to reoccupy hazard zones without clearance from local emergency officials, KTUU reported.

Small sea level changes were still possible, KTUU reported.

Agencies