The Sea Shepherd Conservation Society said Monday that the Japanese whaling fleet staged an "unprovoked" attack on one of its anti-whaling ships in Antarctic waters.

The incident involving the Bob Barker occurred on Sunday night, when the Japanese harpoon ships Yushin Maru and Yushin Maru 3 crossed the bow of the anti-whaling vessel more than 30 times while dragging steel cables, the environmental group said.

The whaling ships were trying to damage the rudder and engines of the Bob Barker, Sea Shepherd said.

"The assault was an attempt to deter the Bob Barker from blocking the slipway of the Nisshin Maru, where it was preventing the whalers' ability to load whales poached from the Southern Ocean Whale Sanctuary," the environmental group said.

The Bob Barker was six nautical miles behind the Nisshin Maru, the factory ship of the Japanese whaling fleet, which had been sighted for the third time on Sunday morning by the environmentalists.

Japanese whalers used searchlights to blind the Bob Barker's crew and threw ice at the anti-whaling ship, Sea Shepherd said.

This was the second attack on the Bob Barker this month.

Sea Shepherd is waging its Antarctic campaign as it awaits the outcome of an International Court of Justice case on the legality of the Japanese whale hunt.

Australia filed suit against Japan in the World Court, alleging that the Asian nation's whaling fleet violates various international conventions protecting marine species in the Southern Ocean.

Japan, for its part, contends that its whaling activities are scientific in nature and protected by international law. EFE