Activists held on whaling ship

"When you start making demands for the return of hostages that sounds like terrorism to me."

Paul Watson, Sea Shepherd president

A high-seas standoff between Japanese whalers and militant anti-whaling activists in the icy waters of the Antarctic drew the governments of Australia and Japan into the fray yesterday.

At the center of the row are two Sea Shepherd Conservation Society activists who were detained on one of the Japanese ships after boarding it to demand an end to the annual slaughter of the giants of the seas.

Sea Shepherd president Paul Watson said Japan's whaling authorities had refused to release the men until he agreed to stop disrupting the hunt, and vowed he would not bow to "terrorist" tactics.

"When you start making de-mands for the return of hostages that sounds like terrorism to me," he said from on board the Steve Irwin, the Sea Shepherd ship that is chasing the Japanese whaling fleet.

Japan it wanted to release the two men, Australian Benjamin Potts and Briton Giles Lane, but that it was waiting for Sea Shepherd to respond to its overtures.

"The ship has been sending messages to hand the two individuals back to Sea Shepherd. But so far the group has not re-sponded," government spokesman Nobutaka Machimura told reporters in Tokyo.

He said the incident would not affect ties with Australia.

"I do not believe this will affect diplomatic relations, but their actions are very dangerous and interfere with legal activities conducted in the public ocean," Machimura said.

"The Japanese government strongly condemns these acts," he said.

Australian Minister Stephen Smith said Japan had agreed to release the men after being contacted by Australian officials.

"The most important thing here is the safety and welfare of the two men concerned and we do, as the Australian government, want their immediate release," he told national radio.

Smith to be drawn on whether he considered the two men hostages but said Australian Federal Police were investigating the incident.

Australia one of the strongest critics of Japan's whaling program, which uses a loophole in an international moratorium that allows "lethal research" on the giant mammals.

Japan, which says whaling is part of its culture, is on a mission to kill 1,000 whales in Antarctic waters this southern hemisphere summer.

Sea Shepherd said the two captured activists were assaulted and tied to the radar mast of the harpoon ship Yushin Maru No. 2.

A video on the group's Web site shows the two men clambering over the rails and onto the Japanese vessel from an inflatable.

A spokesman for Japan's Institute for Cetacean Research denied the men had been mistreated, saying they had been given hot meals, a bath and had a good night's sleep.

"They were restrained for a short period [on deck] before being taken to an office," spokesman Glenn Inwood of New Zealand said. "It was the only way -- you couldn't have them running around the deck not knowing what they're going to do."

The institute's director general, Minoru Morimoto, said the men had boarded the Yushin Maru No. 2 after they made attempts to entangle the ship's propeller with ropes and threw bottles of acid onto the decks.

The men were detained because "it is illegal to board another country's vessels on the high seas," he said.

Hideki Moronuki, head of the whaling division of Japan's Fisheries Agency, said Tokyo was seeking Australia's cooperation to end the standoff.

"Previously, Japanese ships have been physically attacked and harassed by Sea Shepherd and Greenpeace," he said.