The incident occurred around 1.15pm on Thursday (January 21).
The unknown item struck the windscreen, causing damage.
Fortunately, no one was injured as a result.
Four young people of school age and dressed in dark coloured blazers were seen in the area at the time.
PC Garry Cook said: “Although no one was injured on this occasion, the outcome could have been completely different.
“There has been several similar incidents in the past in this area, and I would once again reiterate the danger that is posed by recklessly throwing items from such a height.”