A strong 6.6-magnitude earthquake hit off the Solomon Islands on Monday, the US Geological Survey (USGS) said, but no destructive Pacific-wide tsunami was expected.

The USGS said the quake occurred at 0009 GMT, about 133 kilometres (83 miles) southeast of the Pacific nation's capital Honiara, at an estimated depth of about 30 kilometres (19 miles).

Initial reports were that the tremor had caused no damage.

"So far, we've had no reports of damage," a spokeswoman for the Solomons National Disaster Management Centre told AFP.

The Pacific Tsunami Warning Center said "a destructive Pacific-wide tsunami" was not expected, based on the information available.

But Australian seismologists, who measured the quake at 6.7 magnitude, said there was the possibility of a local tsunami, although it was unlikely to cause a Pacific-wide tsunami.

"It's a 6.7 magnitude so it's not a small earthquake, if you look at Christchurch -- that was a 6.3," senior duty seismologist at Geoscience Australia, Dan Jaksa, told AFP, referring to the devastating quake that hit New Zealand's second city last month.

"But it was 140 kilometres (87 miles) southeast of Honiara so it is not likely to cause any damage in Honiara at all.

"They certainly would have felt the earthquake, there would have been some gentle rocking and gentle rolling but no exaggerated peak accelerations in the ground motion."

The Solomons lies in the "Pacific ring of fire," a highly active earthquake zone that regularly experiences earthquakes, and a strong 6.9-magnitude earthquake struck off the islands in June but caused no damage.

A string of tremors rocked the western Solomon Islands in early 2010, with the largest -- at 7.2 -- causing a tsunami estimated at eight feet (2.4 metres).

In April 2007, an 8.0-magnitude earthquake in the same region triggered a tsunami that killed more than 50 people and displaced thousands.