Twenty-one children have been taken to hospital following a crash involving a school bus and a car which left a driver seriously injured.
The bus was travelling to Our Lady and St Patrick's High School in Dumbarton when the collision happened in Renton Road at about 8.40am on Wednesday.
The Scottish Ambulance Service (SAS) sent six vehicles and an air ambulance to the scene.
The 27-year-old man driving the car, a Vauxhall Corsa, was airlifted to the Queen Elizabeth University Hospital (QEUH) in Glasgow in a serious condition.
West Dunbartonshire Council said a number of pupils were being treated for minor injuries.
In total, 23 patients were taken to two hospitals - the QEUH and the Royal Alexandra Hospital in Paisley.
Nineteen children and a woman from the school bus were taken to hospital by ambulance while another two children were taken by relatives.
The driver of the bus was not injured.
A Scottish Ambulance Service spokesman said: "We received a call at 8.40am today to attend a road traffic collision in Dumbarton.
"We dispatched four ambulances, one patient transport ambulance, one paramedic response unit, our helimed air ambulance and SCOTSTAR emergency medical retrieval service to the scene.
"We can confirm that we have taken a total of 21 patients to two hospitals in Glasgow and Renfrewshire - Queen Elizabeth University Hospital and Royal Alexandra Hospital.
"One male patient was taken by helicopter to the Queen Elizabeth University Hospital.
"Two patients were treated at the scene and travelled to hospital with relatives."
The bus was carrying pupils from the areas of Balloch and Old Bonhill.
A council spokesman said: "Enquiries are ongoing to establish the circumstances of the crash.
"All affected parents and carers have been informed. Parents needing any information should contact the school."
Renton Road was closed between Dalreoch station and the slip road to the A82 following the crash.
Police are appealing for information about the incident.
Inspector Adam McKenzie said: "We are still conducting enquiries to establish the circumstances of the crash and I am appealing to anyone who may have been travelling on the road and who may have information which could assist in our investigation to contact us."
Anyone with information is asked to call road policing officers at Dumbarton police station via 101, quoting reference number 0801 of August 23.