Three people have died following a three-vehicle collision involving a Citylink bus on a road in rural Aberdeenshire.

Police Scotland said four other people had been taken to Aberdeen royal infirmary, with one person airlifted and three travelling by ambulance. Their injuries are described as serious but not life-threatening.

The fatalities were confirmed as police described a challenging operation for the emergency services, which required 25 firefighters at the scene including a heavy rescue unit and involved four people being cut from their vehicles.

The accident happened at around 4.30pm on the A90 at Glenbervie, and involved two cars – a red Renault Megane and a silver Ford B-Max – as well as the bus. Police confirmed that the male bus driver had sustained minor injuries, but none of the bus passengers were injured.

Road policing Ch Insp Stewart Mackie said: “This has been a challenging incident for the emergency services to deal with and my thoughts are with the families of all those affected by this.”

He called for anyone who witnessed the collision to contact the police, and warned that the road around Glenbervie and Drumlithie was likely to remain closed in both directions for some time to allow an investigation to take place.

Mackie said: “This is likely to be a complex enquiry that will take some time and I am grateful to the public for their patience while this is carried out.”

A Scottish Citylink spokesman said: “One of our coaches travelling from Glasgow to Aberdeen was involved in a serious multi-vehicle accident this afternoon on the A90 near Glenbervie Junction. Our immediate thoughts are for those involved in the incident.

“Safety is our absolute priority and we will assist police with their inquiries into the circumstances. There were no reported injuries to passengers travelling on the coach and they were provided with alternative transport to take them to Aberdeen bus station.”