Three drivers have reported having their cars damaged by pellets as they drove near Stane Street yesterday morning (Jan 9).
The victim reported their car window had smashed and a passenger had suffered minor injuries.
It happened as they drove on the A29 at Adversane, near Billingshurst at around 7.30 yesterday morning.
Two similar reports came in from drivers at the same location, near Stane Street, following the first report on Sunday.
Armed officers and the police helicopter attended the scene to search for a suspect.
Sergeant Sarah McManamon said:
"We believe the vehicles could have been shot at by someone using a catapult or BB gun. This is a criminal act and could have caused a serious injury or even a fatal collision."
"We are investigating and would like to hear from anyone who saw this happen or has any dashcam, mobile phone or CCTV footage of the incidents to come forward.
"We will be stepping up patrols in the area and if anyone has any concerns, please speak to one of our officers."
Report online or ring 101 quoting serial 217 of 08/01 or alternatively contact the independent charity Crimestoppers anonymously.