A 16-year-old remains in a critical condition after he was hit by a car in Plashet Road, according to police.
Officers were called to Plashet Road at about 5.20pm on Saturday after separate reports of a fight and a collision involving a vehicle and a cyclist.
Detectives have since linked the two incidents and arrested a 26-year-old man on suspicion of attempted murder. He has been released on police bail until early February pending further enquiries.
The teenage cyclist was taken to hospital suffering a head injury.
Enquiries are continuing. Anyone with information should call Trident on 020 7721 7355 or 101 quoting Operation Gazanta.
Alternatively contact Crimestoppers anonymously on 0800 555 111.
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