The US Geological Survey says an earthquake with an estimated magnitude of 5.8 struck near Tonga today.
The USGS reported the moderate quake as striking at just before nine about 520 kilometres north-west of the Tongan capital. Nuku'alofa.
Its depth was 588km beneath the surface.
The 5.8 reading was based on the open-ended Moment Magnitude scale, now used by US seismologists, which measures the area of the fault that ruptured and the total energy released.