Japan temporarily halted its hunt in mid-January after confrontations with both Greenpeace and the militant anti-whaling group Sea Shepherd Conservation Society, according to Kyodo News agency.

Late last month, the vessels each group had sent to pursue the whalers returned to port to refuel.

The Japanese fleet decided to resume whaling because the threat of being interfered with had faded, Kyodo quoted unidentified Fisheries Agency officials as saying.

Japan has staunchly defended its annual killing of more than 1,000 whales, conducted under a clause in International Whaling Commission rules that allows whales to be killed for scientific purposes.

Critics dismiss the Japanese program as a disguise for commercial whaling, which has been banned by the IWC since 1986. -- AP