Police are urging motorists to be vigilant after three cars were hit by airgun pellets while travelling at speed on a busy motorway.
One driver's face was cut after a pellet shattered the front passenger window, forcing him to pull his Peugeot 206 on to the hard shoulder and call for help.
The same evening an Audi A4 was struck on the rear nearside, causing a large dent, and another car was hit in the same place, smashing the rear passenger window.
Kent Police said all the incidents occurred between 6pm and 7pm on Tuesday on the London-bound section of the M20 at the junction with the M26.
Police chiefs said they were focusing all their efforts on catching whoever is responsible as the attacks happened when the motorway was at its busiest with commuter traffic.
Chief Inspector Jon Kirby said: "We are extremely concerned that someone appears to be firing projectiles at fast-moving vehicles. The consequences of this are horrific.
"Whoever is doing this clearly hasn't thought through the consequences of his or her actions and needs to be caught immediately. We are focusing all of our efforts on doing this.
"In the meantime, I urge all motorists using the M26 to be aware of what has taken place and to report any suspicious activity to police."
The motorway and a footpath are separated by a 3ft-high timber rail fence and beyond it is a dense area of stinging nettles and brambles.
Anyone with information is asked to call Kent Police on 101 or Crimestoppers on 0800 555 111.