A magnitude-6.4 earthquake struck in waters off the Pacific nation of Tonga, according to the US Geological Survey.
The quake struck approximately 84 kilometres north of the kingdom's capital Nuku'alofa at a depth of approximately 100 kilometres, the USGS reported on Monday.
No tsunami warning was issued and no information about damage or possible victims was immediately available.
Australia's Bureau of Meteorology said there was no tsunami threat to Australia.
Tonga sits on the so-called Pacific Ring of Fire, an area known for seismic upheavals and volcanic eruptions.
On Saturday, at least 222 people were killed in Indonesia when a volcano-triggered tsunami devastated a stretch of the country's coast.
