A Japanese whaling ship and an anti-whaling protest vessel collided in icy seas off Antarctica, with both sides blaming the other for the crash .

No-one was injured though both ships were damaged in Sunday's collision.

Anti-whaling group Sea Shepherd, which each year tries to harass the whaling fleet into ending its hunt, said it had been the victim of a lengthy attack by whalers.

The group said the whaling vessels spent hours dragging steel cables across the bows of the Sea Shepherd ships in a bid to damage the rudders and propellers.

Japanese ship Yushin Maru then struck Sea Shepherd vessel Bob Barker as it crossed too closely in front of the protest ship, damaging its bow and anchor, said Bob Barker captain Peter Hammarstedt.

"It was an unprovoked attack and they carried it out ruthlessly," Mr Hammarstedt charged.

Japan, meanwhile, insisted that Sea Shepherd was to blame.

The Tokyo Institute of Cetacean Research claimed that protesters on two inflatable boats from the Bob Barker had dropped ropes in front of the Yushin Maru, which became entangled in the ship's propeller.

The Bob Barker then drew too close to the Yushin Maru, colliding with its stern and damaging the whaling ship's hull and railing, the institute alleged.

"Our research whaling is legitimate activity allowed under international treaty," Japan's Fisheries Agency said.

"Sea Shepherd's violent sabotage, which is threatening the lives of crew members and causing damage to our ships and equipment, cannot be tolerated."