Six riders were injured in a startline pile-up at Cheshire's Oulton Park racetrack on Monday.
The crash happened at the start of the warm-up lap for one of the support races to the British Superbike Championship, the ABK Beer 0% BMW F 900 R Cup Race.
The event was immediately red-flagged and marshals and medical teams came to assist those who were injured, with six being taken to the circuit's medical centre and treated by the BSB Medical Team.
Two of the riders – one them having been knocked unconscious during the crash – were then taken by air ambulance to nearby hospitals.
The BMW race was ultimately cancelled for the day, and the championship support race will be held later in the season at a different track.
A medical update posted by the championship organisers has detailed the injuries sustained by each rider.
The statement reads: "Katie Walker sustained a head injury resulting in a period of unconsciousness. She was treated at the Medical Centre before being transferred by Air Ambulance to Aintree Hospital for ongoing assessment and treatment. Katie has had a brain scan and at this time is stable and does not require an operation. She is being kept in Aintree Hospital for close observation.
"Mark Evans sustained a fractured left fibula and was treated at the Medical Centre and will attend hospital for ongoing care.
"Scott McFarlane sustained minor injuries and has been declared fit to ride at the next event.
"Jim Lee sustained a minor head injury and soft tissue injury to his left foot and will be reviewed to race prior to the next round.
"Jamie Hanks-Elliott sustained a soft tissue injury to her left leg and will be reviewed to race prior to the next round.
"Lee Devenport was treated for neck pain and was transferred by ambulance to Stoke Hospital for ongoing assessment and treatment."
Earlier in the day, British Superbike rider Rory Skinner was taken to hospital following a crash in the warm-up session, during which his crash helmet came off. He was briefly unconscious at the scene and was taken to the circuit medical centre for assessment and stabilisation, at which point he was conscious and talking to a relative.
He was then transferred by ambulance to the Royal Stoke University Hospital for scans and further assessment, before returning to the circuit paddock later in the day, but did not take part in any further racing.
On track, all three of the British Superbike races at Oulton Park over the bank holiday weekend were won by Hager PBM Ducati rider Glenn Irwin, to take an early championship lead.
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