A car travelling towards Attleborough was damaged after a cyclist threw his bike into oncoming traffic.
The incident happened on Friday on the A11 at approximately 1pm when the victim was travelling to the south Norfolk town from Wymondham.
She saw a male pushing a bike towards her so pulled out to give the cyclist sufficient space to pass. The cyclist has then picked up his bicycle and thrown it at her vehicle causing damage.
The victim was not injured but was said to be “very shocked” from the incident.
The cyclist is described as being white, in his 30s with shoulder length hair wearing a red long sleeved fleece and black cycling leggings.
Police are now appealing for information.
Officers are keen to hear from anyone who may have witnessed the incident or saw the male walking his bike on the A11 before or after the incident.
Anyone with information should contact Sergeant Gary Hodges at Thetford Police Station on 101 or call the independent charity Crimestoppers anonymously on 0800 555 111 or via their anonymous online form at www.crimestoppers-uk.org.