LONDON - Rescuers in Scotland say they have guided 44 pilot whales stranded in an estuary back to sea, but 25 other whales from the pod did not survive the incident and died.

Many of the animals died overnight after the pod of whales became stranded at the Kyle of Durness in Scotland's far north at low tide on Friday.

The British Divers Marine Life Rescue said many of the whales had been left on their sides, on top of each other or upside down so they were breathing in sand.

A team of rescuers refloated some of the whales using inflatable pontoons as the water returned.

It said Saturday that post-mortem examinations would be carried out to determine what caused the stranding and the deaths.