Ottawa - A group of animal rights activists observing Canada's annual harp seal hunt were arrested on Sunday for getting too close to hunters killing the animals off the eastern coast, officials said.

The six activists belong to the Humane Society of the United States (HSUS), which says the hunt is cruel and should be scrapped. This year, 325 000 young seals will be shot and clubbed to death on ice floes, mainly for their pelts.

In addition to six activists, a freelance cameraman working for Reuters Television was detained. They were on board a small craft near the Magdalen Islands in the Gulf of St Lawrence, and they broke the law by coming within 10m of the hunters, officials said. They were later all released.

"We'll investigate, get statements and then decide whether to charge them," said Roger Simon of the federal fisheries and oceans ministry, which is overseeing a hunt which started on Saturday.

Unseasonably warm weather means the ice is much more broken up than usual, forcing hunters to shoot seals one by one rather than clubbing them en masse on the floes.

Earlier in the day, the activists said a sealing boat had deliberately rammed one of their small craft, damaging the propeller.

Rebecca Aldworth of the HSUS told Reuters by satellite phone that angry hunters had also thrown seal flippers and carcasses at the activists. She said she would ask Canadian police to charge those responsible.

The first part of the hunt, which takes place near the Magdalen Islands, usually takes about 10 to 12 days to complete. This year's quota is just over 90 000 seals.

"So far the hunters have taken 3 000 to 4 000 seals. That's not ridiculously slow, but it's not fast either. It's the lower edge of the norm," Simon told Reuters.

Celebrities such as former French film star Brigitte Bardot and former Beatle Paul McCartney last week pleaded with Ottawa to end the hunt.

Canadian officials deny the hunt is inhumane and say it provides a boost to the local economy while keeping a harp seal population of over five million in check.

The second and larger stage of the hunt, off the coast of Newfoundland, starts on April 4.