An EU naval spokesman in Nairobi has said that Danish special forces have stormed a ship captured by Somali pirates, freeing 25 crew members.

Cdr John Harbour told the Associated Press news agency it was the first time a warship had intervened after pirates boarded a vessel.

Troops in RIBs moved in after a distress signal from the Antigua and Barbuda-flagged vessel Ariella.

The BBC report that it is not clear if the pirates left the ship before the troops arrived.

The special forces, who set out from the Danish warship Absalon, scaled the side of the ship and freed the 25 crew members, who had locked themselves in a secure room, Cdr Harbour said.

Troops were continuing to search the vessel for the pirates, he added.