A powerful earthquake measuring 7.0 on the Richter scale has struck Haiti in the Caribbean.

The epicentre of the quake, which was initially reported a magnitude 7.3 off the coast, was located inland and close to the capital Port-au-Prince.

There are reports that a number of buildings have collapsed close to the epicentre of the earthquake.

The earthquake has prompted a tsunami watch for parts of the Caribbean, including the Dominican Republic, Cuba and the Bahamas.

The Pacific Tsunami Warning Centre said: 'A destructive widespread tsunami threat does not exist based on historical earthquake and tsunami data.

'However, there is the possibility of a local tsunami that could affect coasts located usually no more than a 100km from the earthquake epicentre.'

The earthquake was quickly followed by two nearby, strong aftershocks of initial magnitude of 5.9 and 5.5.

Haiti's ambassador to the US Raymond Joseph said the earthquake was a 'catastrophe of major proportions'.