An earthquake with an estimated magnitude of 6.0 struck near the Pacific island of Tonga on Tuesday but was unlikely to generate a tsunami, Australian officials said.
Geoscience Australia said the quake occurred close to the Tongan capital Nuku'alofa.
The US Geological Service reported the quake as striking just before 8.30 am about 356 kilometres west-northwest from the capital and at a depth of 481 kilometres.
Trevor Allen, a seismologist with Geoscience Australia, said the underwater earthquake was not considered dangerous.
"You certainly won't get a tsunami generated from an earthquake at 480 kilometres (depth)," he said.
Allen said tremors were a common occurrence in the area and generally needed to reach a magnitude of 7.