A fourth whale has died after beaching in the Firth of Forth.

A decision was made to put the mammal to sleep to end any further suffering due to its "poor state of health".

Five pilot whales became stranded after they were initially spotted in shallow waters near the Fife village of Culross on Tuesday.

They were refloated from the mudflats near Torryburn at high tide on Wednesday evening by a British Divers Marine Life Rescue (BDMLR) team, assisted by the coastguard, Scottish Fire and Rescue Service, Special Operations Response Team and Network Rail.

Despite their best efforts, by Thursday two of the whales died while a third was put to sleep.

On Friday, BDMLR announced that the fourth whale had to be put to sleep, while the fifth remains missing.

A BDMLR spokesperson said: "Sadly, the fourth whale that was being monitored by our team became stranded on the shore at Torryburn during Thursday afternoon.

"It was also in a poor state of health by this stage and again a decision had to be made by the veterinarians to put it to sleep and end any further suffering.

"A fifth whale that was sighted only on Tuesday remains missing and may still be in the area.

"We would ask anyone that spots it to please report it urgently to our emergency hotline."

The Scottish Marine Animal Stranding Scheme hopes to reveal the reason why the whales got into difficulty from the post-mortem examinations.

BDMLR thanked all those who have provided support over the past few days.

The spokesperson added: "This has been one of the most protracted, logistically challenging and emotionally draining incidents that BDMLR's medics have had to deal with in recent years.

"Many of our team have been out on all of the days for many hours in freezing cold, windy, wet and muddy conditions trying to help the whales in incredibly difficult circumstances where the odds have constantly been against us.

"It really is a struggle to find the words that convey how truly difficult and heartbreaking this incident was for us all to deal with both physically and emotionally."