A community protest group opposed to new flight paths being trialled by Gatwick Airport were the victim of vandalism on Sunday (August 10).
CAGNE (Communities Against Gatwick Noise and Emissions) said their protest banners were slashed at the weekend.
A spokesperson for CAGNE said two banners next to the A24 were slashed before 6pm on Sunday.
The police have been notified.
CAGNE has urged anyone with information to contact them in confidence by sending an email to firstname.lastname@example.org