A strong 7.0 magnitude earthquake struck the Solomon Islands on Tuesday, with eyewitnesses reporting violent shaking that hurled televisions and other items to the ground.

A tsunami warning was issued for an area of the Solomons coast within 300 kilometres of the epicentre.

"This was a big one," Joy Nisha, a receptionist with the Heritage Park Hotel in the capital Honiara, told AFP. "Some of the things in the hotel fell. Everyone seems OK, but panicky."

An AFP reporter in the capital said the shaking lasted for around 20 seconds.

Power was out in some areas of the city and people were leaving their offices and fleeing to higher ground.

The USGS revised the earthquake's magnitude down from an initial 7.3. (AFP)