A magnitude-7.1 earthquake hit southern Alaska early Sunday morning, awakening residents and shaking buildings in the earthquake-prone region.

The earthquake struck about 1:30 a.m. Alaska time and was centred 83 kilometres east of Anchor Point and 250 kilometres southwest of Anchorage, according to the U.S. Geological Survey.

The agency initially reported it as a magnitude-7.1, but downgraded shortly after to magnitude-6.8 before raising it back to 7.1.

Alaska

The earthquake struck about 1:30 a.m. Alaska time and was centred 83 kilometres east of Anchor Point and 250 kilometresw southwest of Anchorage, according to the U.S. Geological Survey. (Google maps)

In the community of Kenai, located on the Kenai Peninsula, four homes were destroyed and an entire neighbourhood had to be evacuated after a gas leak was reported, Kenai police Chief Gus Sandahl said Sunday morning

A police officer extinguished a fire that started in a house, but flames started coming under a wall, and the officer backed off to let firefighters finish the work, Sandahl said.

A home neighbouring the one on fire exploded hours after the quake, Sandahl said. All firefighters and gas utility workers were accounted for, and there were no reports of injuries.

Crews were "definitely still trying to resolve the gas issue," Sandal said nearly eight hours after the earthquake.

A second home was destroyed in gas leak explosions and another two were fully engulfed in flames before firefighters determined it was safe enough from gas for them to enter the homes, Kenai battalion chief Tony Prior said.

"No injuries. Thank God," he said. "The second one was a major explosion. We're fortunate that no one was hurt."

A shelter was set up at the Kenai Armory for those displaced, and Sandahl said there were about 20 people there.

No injuries reported

The earthquake was widely felt by residents of Anchorage, and there are reports of scattered power outages from the Matanuska Electric Association and Chugach Electric in the Anchorage area. But the Anchorage and Valdez police departments say they have not received any reports of injury or significant damage.

Anchorage resident Ron Barta says his house shook about 1:34 a.m. when the earthquake hit. Barta, 55, says the pictures on the walls started moving, but there was no damage to his house and no one was hurt.

"I was sitting here with the dogs getting ready to go to bed about 1:34 local time. ... I felt a little rumble that didn't quit for about 30 to 45 seconds. It felt like the house moved," said Barta, who is married to an Associated Press reporter.

The violent shaking woke up Associated Press reporter Mark Thiessen, who had been asleep for about two hours when then quake struck.

"I remember the bed swaying back and forth, and loud noises, enough to wake me up even after taking sleeping pills," said Thiessen, 53. "My husband came into the bedroom forcefully saying, 'Get up! Get up!' " he said. "But I was already awake, trying to figure out what was happening."

Barta, who has lived in Anchorage for about 10 years, says Alaskans on social media say the earthquake woke them up.

People were saying on social media that the earthquake "was the biggest I ever felt as long as I have lived here," Barta said.