A magnitude-7.3 earthquake struck in the Pacific Ocean on Saturday at a depth of some 536 kilometres between the island states of Fiji and Vanuatu, the US Geological Survey (USGS) said.
According to the agency, the nearest town is located some 453 kilometres away, on Fiji’s main island of Viti Levu.
Initially, there were no known reports of damage or fatalities.
Some 15 minutes after the quake, a second one occurred in the southern Pacific region east of Australia, this time at a magnitude of 4.7, according to the USGS.
The archipelagos of Fiji and Vanuatu are located in the so-called Pacific Ring of Fire, which is considered the geologically most active zone on Earth.