A strong earthquake with a preliminary magnitude of 6.6 struck Wednesday night in the Caribbean Sea just off the Panama-Colombia border, AP quoted the US Geological Survey as saying.

There was no immediate word on whether were any injuries or damage in the nearby areas, which are not densely populated.

The USGS said the quake was centred about 41 kilometres (25 miles) northeast of Puerto Obaldia, Panama. The epicentre was at a depth of 10 kilometres (6 miles). An aftershock with a magnitude of 4.9 followed about 10 minutes after the original quake.