TOKYO, March 3: Japan on Monday summoned ambassadors from Australia and The Netherlands after it said environmentalists hurled stinging acid onto a Japanese whaling ship, injuring three on board.

Australia, a leading opponent of Japan’s whaling, quickly condemned the latest attack by the militant Sea Shepherd group, which has vowed to stop Japan’s controversial expedition by force if necessary.

Members of Sea Shepherd threw more than 100 brown envelopes containing a white powder and bottles of butyric acid from their own vessel onto the Japanese whaler Nisshin Maru, Japanese officials said.

Butyric acid, a by-product of cheese-making, is used in manufacturing industrial alcohol and can sting the eyes. Sea Shepherd said they threw rotten butter.

Japanese authorities said they were still investigating the substance in the envelopes, which Sea Shepherd said was designed to make the ship’s deck so slippery that the crew cannot work.

Video footage showed the Nisshin Maru playing a recorded warning that the activists faced arrest. Unperturbed, activists on the Sea Shepherd ship then hurled bottles onto the whaler.

Two crew members and two coast guard officers complained of pain after the hour-long attack, the Fisheries Agency said. Three of them required treatment by washing out their eyes.

Japan described US-based Sea Shepherd as “terrorists” and lodged protests with Australia, where the Sea Shepherd’s Steve Irwin vessel last called into port, and The Netherlands, where the boat is registered.

Japan summoned both Australian Ambassador to Japan Murray McLean and Dutch Ambassador to Japan Alphons Hamer and urged them to take measures to prevent the violence, the foreign ministry said.

“That was an inexcusable act to inflict unjustifiable damage to Japan’s ship and to harm the safety of the crew who are operating legally in the public sea,” said Japan’s top government spokesman Nobutaka Machimura.

Sea Shepherd hailed the confrontation, saying it ensured that the ship could not kill whales.

“I guess we can call this non-violent chemical warfare,” Sea Shepherd chief Paul Watson said. “We only use organic, non-toxic materials designed to harass and obstruct illegal whaling operations.” Japan, which says whaling is part of its culture, kills up to 1,000 whales a year using a loophole in a 1986 global moratorium that allows “lethal research” on the giant mammals.

Activists from the US-based Sea Shepherd had also hurled bottles onto the Japanese whaler in January. Two activists, a Briton and an Australian, hopped onto the vessel, setting off a two-day standoff.

Australia’s new government, which took office in December, has ramped up pressure on Japan against its killing of whales, which are beloved by Australians and sustain a major whale-watching industry.

Australian Foreign Minister Stephan Smith urged both sides to show restraint.

“I absolutely condemn actions by crew members of any vessel that cause injury or have the potential to cause injury to anyone on the high seas,” Smith said.

The incident came as Japan held a seminar with officials from 11 developing states that have recently joined or are considering joining the deadlocked International Whaling Commission.—AFP