High winds and choppy seas halted vessels which were set to leave on a six-week mission to kill 38 minke whales.

Iceland's government said it was embarking on a scientific whaling programme, and authorities had been due to issue permits on Friday.

BBC News Online's guide to the key species in the whale-hunting debate At-a-glance

They say the mammals have become so abundant since a worldwide moratorium on commercial whaling that they are threatening stocks of fish, including cod.

But the decision was attacked by the UK and US Governments, as well as animal welfare groups.

The International Fund for Animal Welfare (Ifaw) says there is no scientific basis for the operation, and that Iceland cannot use science to camouflage its desire to resume commercial whaling.

In Britain, the Royal Society for the Prevention of Cruelty to Animals is stopping short of calling for a boycott of Icelandic products, but it is asking consumers to think twice before buying fish from the island.

Iceland's own tourism industry has joined in the criticism, fearing that the decision could damage the country's image, and threaten the increasingly popular whale-watching business.

Norwegians do it, Russians do it, Japanese do it, Americans do it, why can't we? Gisli Vikingsson Marine scientist

"Whaling is part of Iceland's past, and must remain so," Greenpeace Executive Director Gerd Leipold said in a statement.

"While we don't expect to change everyone's minds, Greenpeace hopes that we are able to give many Icelanders the confidence to say no to whaling - forever."

Objection

Three ships were due to set sail from undisclosed locations over the coming days to avoid possible protests.

ICELAND AND THE WHALE 1986: International moratorium on commercial whaling 1989: Iceland halts whaling 1992: Iceland quits IWC 2002: Rejoins IWC 2003: Resumes whaling

Iceland has not hunted whales since 1989.

It left the International Whaling Commission, the body that regulates world whaling, in 1992.

But it rejoined in 2002 on condition that it was allowed to register its objection to the moratorium on commercial whaling that has been in place since 1986.

Earlier this year, it said it wanted to hunt 100 minke, 100 sei and 50 fin whales.

Rainbow Warrior

The original proposal was discussed at the recent Berlin meeting of the IWC - but not voted on.

Icelandic officials say that by restricting its operation to 38 minke, the country is showing it is ready to compromise with its critics.

Stocks of minke are internationally acknowledged to be abundant, they say.

The environmental organisation Greenpeace has recalled its flagship Rainbow Warrior for a mission to Iceland.

The ship, which campaigned against Icelandic whaling on its maiden voyage in 1978, is due to arrive in two weeks.