Alaska earthquakes: Twin tremors cause extensive damage as they strike near Anchorage

Area hit by a 7.0 magnitude earthquake closely followed by a 5.7 magnitude aftershock

A powerful 7.0 magnitude earthquake followed by a 5.7 magnitude tremor have caused extensive damage around parts of Alaska after striking near Anchorage.

A tsunami warning was issued for areas of the Alaskan coast - forcing people to head to higher ground - before later being lifted.

The warning covered coastal areas of the Cook Inlet and southern Kenai Peninsula after the initial tremor hit about 7.5 miles north of the city, the United States Geological Survey (USGS) reported.

Part of an off-ramp near Anchorage international airport collapsed, leaving a car stuck between deep chasms in the concrete. Several cars crashed at a major intersection in Wasilla, north of Anchorage.

Anchorage Police Chief Justin Doll said he had been told that parts of the Glenn Highway, a road that runs northeast out of the city past glaciers and mountains had “completely disappeared.” However, Mr Doll said that there were also reports of damage to a number of bridges, there were no early reports of serious injuries or deaths.

People went back inside buildings in Anchorage after the first earthquake, but the aftershock sent them running back into the streets again.

Images and video started to appear of the damage, with local newsrooms some of the first to highlight the state of their offices. Former Alaska Governor Sarah Palin said that her house had been damaged.

Lawyer Hank Graper was driving when the quake struck. He told the Associated Press that he only realised it was an earthquake after he saw traffic poles at the side of the road swaying.

Mr Graper called it the most “violent” earthquake he’s experience in his 20 years in Anchorage.

Brandon Slaton from Kenai, Alaska, was soaking in the bathtub when the earthquake struck – the force of the tremor eventually threw him out of the bath.

“It was anarchy,” Mr Slaton told the Associated Press. There’s no pictures left on the walls, there’s no power, there’s no fish tank left. Everything that’s not tied down is broke.“

Alaska averages 40,000 earthquakes per year, with more large quakes than the 49 other states combined.

The state has been hit by a number of powerful quakes over 7.0 in recent decades, including a 7.9 last January southeast of Kodiak Island. But it is rare for such earthquakes it hit so close such a heavily populated area.

The USGS expect a number of aftershocks to hit over the next week - with the possibility of thousands of smaller tremors.

Associated Press contributed to this report