Eighteen people have been injured after toxic gas used to kill rodents escaped from a ship docked at a harbour in Northern Ireland.

Cargo on the vessel at Warrenpoint, Co Down, had become wet and unstable and a cordon has been established.

The gas is aluminium phosphide, a pesticide used to kill small mammals such as moles and rodents.

Police in the Irish Republic have been informed of the potential of the chemical compound to drift into their area.

A Police Service of Northern Ireland spokesman said: "It is believed that there are five casualties suffering from the effects of exposure to the gas."

A 50m cordon has been set up around the ship.

A Northern Ireland Ambulance Service spokesman said: "We have 18 patients. It is a chemical incident on a ship. Nine are en route to Daisy Hill Hospital and nine are at the scene and they will be transferred to Craigavon Area Hospital."

A Northern Ireland Fire and Rescue Service spokeswoman confirmed they were dealing with a major incident.