Unusually warm weather means the floes are a fraction of their normal size and thickness, prompting hunters to kill the seals individually rather than clubbing them to death en masse as they cluster on the ice in pools of blood.

"It's slow going. The ice is not full of seals all over the place," said Roger Simon of Canada's federal fisheries ministry, which oversees the hunt.

The crack of rifle fire could be heard continually as hunters in boats shot seals as they lay on tiny floes and then dashed over to the bodies in hopes of retrieving them before they slipped off the ice and sank.

Once the animals are killed, they are skinned and taken into the hunters' boats. The pelt is taken to make coats while the rest of the carcass is usually left behind.

At one point a hunter, frustrated at the activists' presence, picked up the bloody carcass of a skinned seal and threw it at a small inflatable craft full of protesters and journalists. It hit the boat and sank.

One sealing boat steamed straight toward the journalists' craft and turned at the last moment, sending a wave crashing over the observers.

Canada says the hunt gives the local economy a crucial boost and helps keep a harp seal population of almost six million animals in check.

The Humane Society of the United States has chartered a 110-foot (30-metre) boat to follow the hunt and is putting film and videos of the killings on its Web site.

"It's disgusting when you stand out here and look at what the seals have been through already. They're clinging on for life as it is, thanks to the effects of global warming," said the society's Rebecca Aldworth.

"I'm really appalled the Canadian government continues to allow this slaughter. There's no need for anyone to be out here killing seals," she told Reuters from the hunting zone.

CANADA SAYS KILLINGS ARE HUMANE

Prime Minister Stephen Harper said Canada was behaving responsibly and would enforce rules ensuring that the seals were killed humanely.

"Unfortunately here we're to some degree the victim of a bit of an international propaganda campaign," he said on Friday.

Celebrities such as former French film star Brigitte Bardot and ex-Beatle Paul McCartney called on Ottawa this week to stop the hunt.

Aldworth repeated calls for an international boycott of Canadian seafood to protest what she said was "incredible cruelty at the hunt, including dragging conscious seals across the ice with boathooks, shooting seals and leaving them to suffer in agony and skinning seals alive."

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