Somali pirates have started to cut off their hostages' limbs in a bid to extract even greater ransoms from the owners of the ships they capture.

The horrific new tactic was used last Friday on the Vietnamese captain of a ship being held in the Somali pirate lair of Haradhere.

Chao-I Wu's right arm was cut off after negotiations to pay a $3million ransom for his fishing ship, the FV Shiuh Fu-1, broke down.

Afterwards, the pirates allowed Mr Wu's fellow crew members to call their families and describe what had happened.

'This group of pirates were allowed the crew to call their relatives for only a few minutes - just long enough to tell their families about the amputation.

'They begged their relatives to pay and some of them were crying.

'It was a message to the owner and their families that if the owners don't pay this amount of ransom they will hurt another crew member', a pirate source told the Somalia Report news service.