Three powerful earthquakes with magnitudes of 7.8, 7.7 and 7.1 struck near the South Pacific nation of Vanuatu in the space of just over one hour on Thursday, seismologists said.
The first magnitude 7.8 quake sparked a region-wide tsunami alert and was quickly followed by two other strong earthquakes, the US Geological Survey said.
The initial earthquake struck 294 kilometres from Vanuatu’s Espiritu Santo island at a shallow depth of 35 kilometres at 9:03 am (0330 IST Thursday), and was followed just 15 minutes later by a 7.7 quake.
The second quake, the magnitude of which was revised upwards from 7.3, hit 330 kilometres from Luganville on Espiritu Santo island at 9:18 am.
Residents in the area were shaken again by a 7.1 magnitude quake at 10:13 am about 280 kilometres northwest of Luganville.
Aftershocks also shook the region, with a 5.7 quake shaking Vanuatu nearly two hours after the first big quake, and a 5.3 tremor striking near Samoa, causing panic in the islands that were devastated by a tsunami last week.
A total of 184 people are confirmed dead in Samoa, American Samoa and Tonga following a tsunami sparked by an 8.0 magnitude quake on September 29. Six remain missing.