Strong earthquake strikes off Tonga

A 6.1 magnitude earthquake has struck off Tonga.

An undersea earthquake with a magnitude of 6.1 has struck off the South Pacific island nation of Tonga, the US Geological Survey says.

The quake, at a depth of 97 km, was located 180 km south-southwest of Neita in Tonga.

No tsunami warning has been issued and there are no immediate reports of damage or casualties from the quake.