(Updates with Japan reaction)
By Michael Perry
SYDNEY, Feb 6 (Reuters) - An anti-whaling protest ship and a Japanese whaling vessel collided in the Southern Ocean on Friday as the Japanese tried to haul a dead whale on board, and the incident prompted a sharp rebuke from Tokyo.
No one was injured in the collision, which caused minor damage to the stern of the Japanese ship, the hardline anti-whaling group said.
The Sea Shepherd group’s ship, the Steve Irwin, collided with the Yushin Maru 2 as the harpoon vessel tried to block its attempt to prevent the transfer of a dead whale up the slipway of the factory ship Nisshin Maru, said Steve Irwin Captain Paul Watson.
"We were in the process of blocking the transfer from the Yushin Maru 2 when the Yushin Maru 1 moved directly in front of the bow to block us," Watson said in a statement.
"I could not turn to starboard without hitting the Yushin Maru 1. I tried to back down but the movement of the Yushin Maru 2 made the collision unavoidable," he said.
Watson said the collision crushed a railing at the back of the Japanese ship though there were no reports of injuries.
But the Japanese authorities were quick to complain.
"It is an act of violence and it is unforgiveable," said Shigeki Takaya, an assistant director of the Far Seas Fisheries Division at Japan’s fisheries ministry.
Tokyo said the incident followed a series of protest activities a day earlier by the anti-whaling group, which it said threw bottles of acid at the Japanese ships and ropes into the water to tangle up the ships’ propellers.
The Steve Irwin was continuing to tail the Nisshin Maru to prevent whales being hauled on board.
The Sea Shepherd Conservation Society has been blamed for collisions with the Japanese Antarctic whaling fleet in recent years, as well as high-seas boardings and stink bomb attacks.
Its confrontational tactics have been widely criticised both by pro-whaling groups and fellow environmentalists, although it has also attracted high-profile supporters.
Both the Australian and New Zealand governments oppose the Japanese whale hunt, but have called on whalers and anti-whalers to remain peaceful in the dangerous Southern Ocean.
The annual Japanese whale hunt is aimed at catching about 900 whales. Although Japan officially stopped whaling under a 1986 global moratorium, it continues to take hundreds of whales under a loophole allowing whaling for research purposes. Much of the meat ends up on supermarket shelves and dinner tables. (Additional reporting by Yoko Nishikawa in Tokyo) (Editing by Bill Tarrant)