Anti-whaling activists with the Sea Shepherd Conservation Society announced that they have caught up with Japan's whaling fleet near Antarctica.
Sea Shepherd said on Monday it had found all five Japanese vessels in the Southern Ocean and had photographic evidence that showed three minke whales had been killed and were being cut up on the factory ship Nisshin Maru. The group also claimed to have information about a fourth whale having been killed.
The society alleged that the whales had been taken inside an internationally-recognized whale sanctuary.
It is the first time the environmentalists and the whaling fleet have crossed paths this season.
The U.S.-based group regularly sends small boats to harass the Japanese fleet during its annual whale hunt. It is known to use stink bombs, dye markers, laser beams and other objects to attempt to disrupt the Japanese whalers.
Commercial whaling is banned under an international treaty, but Japan continues to hunt using a loophole that allows whaling in the name of science, a practice condemned by environmentalists and anti-whaling nations.
Sea Shepherd Australia is criticizing the Australian government for backing away from pre-election promises to send a ship to monitor the Japanese whaling fleet. The government has instead said it will use a plane to observe Japanese actions in the area.
Australia has been critical of Japanese whaling activities. The two countries are waiting for a ruling on an Australian challenge to the legality of the Japanese whale hunt, expected from the International Court of Justice later this year.