HOBART, Australia (AP) _ Rangers buried about 100 pilot whales today after rescuers struggled for days to save pods of whales that beached themselves on Tasmania.

Experts remained puzzled as to why such intelligent animals blindly return to deadly shallows off the island state south of Australia.

The burials came after a rescue operation that began Saturday afternoon was completed this morning, when eight whales were moved into deeper water.

A spotter plane found no other strandings or any pods close to land, officials said.

Rescue efforts were continually frustrated over the weekend as grounded whales were freed from shallow water and moved back out to sea only to become beached at another section of the 12-mile stretch of coast.

The initial stranding on Saturday was at Marion Bay, on Tasmania's southeast coast. Rescuers comforted about 50 whales then either returned them to deeper water or put them on trucks and took them to another location where they were returned to the sea.

But just as rangers and volunteers were completing that rescue, another big stranding occurred a beach to the north, and a second group came ashore at Marion Bay.

Further complicating the rescue, some of the whales which had been trucked to another location would not head out to sea.

Tasmania's Parks and Wildlife Service director Max Kitchell said since Saturday about 100 whales were put back into the water, but there was no way of knowing how many restranded.

``I'm very confident that we saved more than 40, and it might be double that,'' he said.

Nor does he know whether they all came from the same pod, although analysis of samples taken from the dead whales by University of Tasmania scientists should determine that.

It was the first major stranding on Tasmania's east coast for about six years, although there were three beachings of much bigger sperm whales on the west coast early this year.

Kitchell said once caught in the shallows, a whale sends out distress calls that bring in others to help.

``But why, when we get them back out to sea and there's no more on the beach to call them they still come in again, we just don't know,'' Kitchell said.