United States seismologists say a 6.4-magnitude earthquake hit the Santa Cruz islands last night.
But no tsunami warning was issued and there are no reports of damage.
The US Geological Survey says the quake struck at a shallow depth of 10km about 355km north of Luganville, part of the Vanuatu archipelago, just after half past eight last night.
The tremor followed a series of huge quakes last week that triggered a regional tsunami alert.
