Ignoring international protests, a Japanese whaling fleet on Sunday headed for Antarctica to hunt for some 950 minke, humpback and fin whales.

The expedition of six vessels is to last until mid-April, with the Japanese - in keeping with previous practice - declaring that the catch is for "research purposes."

The Kyodo agency reported that the expedition aimed to kill around 850 minke whales, as well as 50 each of the humpback whale - which are a favourite of whale watchers for their acrobatic displays - and fin whales.

The research aims will focus on the contents' of the whales' stomachs and the age of the animals. After the fleet returns, the whale meat will be sold on fish markets in order, by official Japanese accounts, to finance future whaling fleets.

By declaring the whale catch as meant for scientific research, Japan's whaling industry is able to circumvent the international ban on commercial whaling declared in 1986.

At ceremonies before the fleet embarked on the expedition, Japanese officials blasted the "evil blockade tactics of environmental groups" and vowed that the whaling actitivies would continue in the future.

According to the environmentalist group Greenpeace, the fleet was originally to have set out on November 16. But its departure was delayed so as not to put Premier Yasuo Fukuda in an embarrassing situation since he was meeting US President George W Bush on the same day in Washington.