A man died and four others were injured in an incident on a fishing boat at Fraserburgh harbour.
Ambulance crews said that they were called to the Aberdeenshire town on the northeast coast at about 2pm yesterday and fire crews, police and coastguard teams also attended.
Police Scotland said that concerns were raised for a group of men who had fallen ill. Some of the casualties on the docked vessel, Sunbeam, had to be treated with oxygen because of breathing difficulties.
It was not known whether a leak of gas or other substances was the cause. One man was airlifted to Aberdeen Royal Infirmary, while others were treated at the scene.
The Health and Safety Executive and Marine Accident Investigation Branch have been alerted.