Police at Strand Road are investigating a report that a cyclist was struck by a missile thrown from a passing car on Sunday afternoon.
A PSNI spokesman said the cyclist was close to a local hotel at Prehen Road when he was struck on the lower leg.
“Police are keen to learn more about the occupants of a car, a blue Volkswagen Jetta that overtook him,” he said.
Information can be given using the police non-emergency number 101.
Alternatively, it can be provided through the Crimestoppers charity anonymously by telephoning 0800 555 111.