Hurricane Irma smashes Caribbean island of Saint Martin

Hurricane Irma has destroyed four of the "most solid" buildings on the Caribbean island of Saint Martin and may swing north towards the US by the weekend.

The buildings, shared by France and the Netherlands, were struck by the most powerful hurricane ever recorded, said French Interior Minister Gerard Collomb.

Other areas of St Martin were flooded and blacked out, according to reports, and communications between Paris and Saint Martin and Saint Barthélemy were down as a result.

Irma, a massive Category 5 storm that is sustaining record 300kph winds, is expected to move on towards Puerto Rico and the Dominican Republic.

The hurricane's path after that is uncertain, though US weather forecasters said there was a high risk it could turn north and hit Florida over the weekend.

President Donald Trump has ordered a mandatory evacuation of Florida's key west area.