Sydney:
A strong 6.7 magnitude earthquake struck off the South Pacific islands of Wallis and Futuna in the early hours today, following another powerful earthquake off Tonga.
The latest quake hit at 5:15 am local time and occurred 205 kilometres southeast of the Wallis and Futuna capital of Mata-Utu, the US Geological Survey said.
It came less than two hours after a 6.4-magnitude quake struck off Tonga.
Neither generated tsunami alerts and there were no immediate reports of damage.
The undersea quake off Tonga hit at 3:52 am and was 197 kilometres northwest of the town of Hihifo, USGS said.
The epicentre was also at a depth of 10 kilometres.
That tremor was followed less than three hours later by a 5.6-magnitude quake a few kilometres further west.
The region lies in the so-called Pacific Ring of Fire, an area of frequent seismic activity due to collisions between continental plates.