Earthquakes are common in Tonga, which sits on the Pacific Ring of Fire. Photo: Public Domain
Multiple earthquakes struck near Tonga from Friday to Monday.
The US Geological Survey reported a 7.2 magnitude earthquake on Friday morning, 280km south-west of Houma, and around 170km deep.
Kaniva Tonga said no casualties or damage were reported.
On Saturday, a 6.5-magnitude earthquake struck in the Tonga region, but no tsunami alerts arose from it.
On Sunday morning a trio of aftershocks came, around 275 to 290km from 'Ohonua.
The shakes continued in the early hours of Monday, all ranging between magnitude 4.6 and 5.8.
They were between 10 and 28.5 kilometres deep, and 274 to 299km south-west of 'Ohonua.
Earthquakes are common in Tonga which sits on the circum-Pacific seismic belt, known as the Ring of Fire.
The world's greatest earthquake belt, the Ring of Fire is found along the rim of the Pacific Ocean, where the Pacific Plate meets many surrounding tectonic plates.
About 81 percent of the world's largest earthquakes occur on this seismic belt.
Tonga experiences an average of three magnitude 6-plus earthquakes a year, although few trigger tsunami alerts.
According to the United States Geological Survey, Tonga, Fiji and Indonesia probably experience the most earthquakes per unit area, although the sparse seismic instrumentation in those areas doesn't allow the recording of all the smaller earthquakes.
Meanwhile, a 5.3 magnitude earthquake hit Vanuatu on Sunday night, 40km east-north-east of Luganville, but it was 122.5km deep.