A lorry window was smashed as yobs hurled bricks from motorway bridges at those driving below.
Police have stepped up patrols after five similar incidents in Sittingbourne over four days.
At around 5.40pm on Sunday, October 3, officers received three reports of vehicles travelling on the M2, below the Sawpit Road bridge, having their windscreens and windows damaged.
Witnesses did not see anybody on the bridge.
At around 4.40pm on Wednesday, October 6, two more reports were received and this time witnesses said they saw a man throwing bricks from Ruins Barn Road, into the paths of lorries.
One lorry driver’s window was smashed.
The investigation is ongoing and anyone with information, or dash cam footage that captures the incidents should contact Kent Police.
Ch Insp Joel Mitchell, Kent Police’s District Commander for Swale, said: "These reports are really concerning, and this type of behaviour is very reckless and has the potential to cause fatalities.
"Not only can those responsible cause serious injuries to innocent people but they also risk obtaining a potential prison sentence."
Anyone with information about the incidents can call Kent Police on 01795 419119 quoting the reference number 46/197053/21.
You can also call the charity Crimestoppers anonymously on 0800 555111 or complete the online form at crimestoppers-uk.org