Police officers are "seriously injured" and a section of motorway is closed after a crash on Sunday night.

One vehicle was involved in the crash which happened shortly before 10pm on the M90 between junctions four and five near Kelty in Fife.

The driver suffered head injuries.

The officers had been responding to a report of a drunk driver, according to Chief Superintendent Stewart Carle.

The head of the Road Policing Unit tweeted that his thoughts were with "both my officers" after the crash.

He wrote: "I heard dreadful news just after 11pm last night that a @polscotrpu crew crashed on M90 near Kelty responding to report of a drunk driver, and seriously injured.

"Grateful to motorists who assisted rescue and 999 responders who gave treatment. Thoughts with families of both my officers."

Police Scotland in a statement said: "About 9.40pm on Sunday 6 October 2019 a one vehicle road traffic collision happened on the northbound carriageway of the M90 Edinburgh to Perth motorway about 1.5 miles north of Junction 4 (Kelty). 

"A marked BMW 330 patrol car containing two police officers left the roadway coming to rest on the grass verge.  Emergency services attended at the scene and the road was closed.  The driver was removed from the vehicle by Fire and Rescue Service personnel and was taken to Edinburgh Royal Infirmary."  

It added: "He was later transferred to Western General Hospital in Edinburgh with neurological injuries.  The passenger was taken to Ninewells Hospital with back injuries.  The road at the scene was closed while a full crash scene investigation was carried out.  The road is now fully open."

The Scottish Fire and Rescue Service were called to the scene at 9.58pm with three engines sent to the scene.

Chief Inspector Mark Patterson from Road Policing East said "The officers in the patrol car were responding to the report of a drunk driver on the motorway when the collision happened. 

"Our thoughts are with both officers and their families at this time.  I would appeal to anyone who may have witnessed this collision to call Police Scotland on the 101 number quoting the incident reference number 3798 6/10.”