Major cruise lines operating in the Caribbean have been forced to alter their itineraries as Hurricane Irene sweeps through the region.

Carnival Cruise Lines and Royal Caribbean International have both modified plans as the storm heads toward the cruise hub of Puerto Rico.

The storm was upgraded to a hurricane by the US National Hurricane Centre in Miami on Monday morning.

It has already caused substantial damage to the island of St Criox.

Ships with revised itineraries include Royal Caribbean’s Oasis of the Seas and sister ship Allure of the Seas, Freedom of the Seas and Serenade of the Seas.

Carnival Miracle has also been rerouted.

The storm is due to reach the east coast of the Dominican Republic later.