A strong 7.3 magnitude earthquake has struck near Vanuatu's capital Port Vila, damaging buildings and other infrastructure.

The quake happened at 12:47 local time (01:47 GMT) at a depth of 57.1km, according to the United States Geological Survey (USGS).

It briefly triggered a tsunami alert for parts of the Pacific island nation, but officials said as of 14:14 local time that the threat had passed.

The extent of damage remains unclear, but there are unconfirmed reports of at least one death.

Dan McGarry, a journalist living in Port Vila, said police at the Vila Central Hospital told him that one person has died.

Posting on X, McGarry said he saw three people "seriously injured" on hospital gurneys awaiting treatment. The earthquake was the "biggest one I've seen in 20+ years," he added.

Footage on social media shows collapsed buildings, cars hit by fallen panels and furniture strewn on floors inside homes. Residents are reporting patchy communications.

The US embassy in Port Vila is among the damaged buildings, according to photographs posted online.

US officials said the building sustained "considerable damage" and will be closed until further notice.

"Our thoughts are with everyone affected by this earthquake and the US government will work with closely with our partners in Vanuatu," the embassy in Papua New Guinea said in a statement.

Michael Thompson, director of the Vanuatu Jungle Zipline adventure company, told AFP news agency that he saw bodies lying in the streets.

"There's multiple buildings that have come down around town. There's a big rescue operation on the way to clear out people who are possibly alive in the building," Mr Thompson said, in a separate video posted to Facebook.

"Most of the communications have gone."

USGS reported at least four aftershocks around Port Vila - with magnitudes ranging from 4.7 to 5.5 - in the two hours after the first earthquake.

Authorities in neighbouring New Zealand and Australia said there was no tsunami threat for their countries.

Australia also said it "stands ready to support Vanuatu as the extent of the damage is assessed".

"Vanuatu is family and we will always be there in times of need," Foreign Minister Penny Wong wrote on X.

Vanuatu, a low-lying archipelago of some 80 islands, is located in a seismically active area and susceptible to frequent large earthquakes and other natural disasters.