Sand Point, Alaska - A 7.2 magnitude earthquake struck off the Alaskan peninsula late Saturday local time, the United States Geological Survey (USGS) said, briefly sparking a tsunami warning.

The USGS revised the quake's magnitude down from an initial 7.4.

The shallow quake hit at 10:48 PM local time Saturday (2:48 AM EDT), about 55 miles southwest of the small town of Sand Point, the agency said.

The National Tsunami Warning Center in Palmer, Alaska, reduced an earlier tsunami warning to an advisory for south Alaska and the Alaskan peninsula.

"For other US and Canadian Pacific coasts in North America, there is no tsunami threat," it said.

"The Tsunami Warning has been DOWNGRADED. A Tsunami ADVISORY is in effect for coastal Alaska from Chignik Bay to Unimak Pass. Kodiak Island & Kenai Peninsula are NOT expected to see impacts," the National Weather Service Anchorage tweeted. "Strong currents or waves expected where Tsunami Advisory is in effect."

Alaska is part of the seismically active Pacific Ring of Fire.

The remote state was hit by a 9.2-magnitude earthquake in March 1964, the strongest ever recorded in North America.

It devastated Anchorage and unleashed a tsunami that slammed the Gulf of Alaska, the US west coast, and Hawaii.

More than 250 people were killed by the quake and the tsunami.