Tonga was hit by the earthquake at 3.04am local time (3.04pm BST).
Damage or injuries have not yet been confirmed on the Pacific nation, which is made up of 169 islands.
No tsunami warnings are currently in alert, according to the Pacific Tsunami Warning Center.
The earthquake struck at a depth of six miles, around 117 miles north-west of the village of Pangai, which is home to 1,800 people.
It struck 154 miles north of Nuku’alofa, which is home to 22,400 people.
This is a developing story, more to follow…