A gang of youths were pictured throwing bottles at road workers from an old railway bridge onto the M61 between junctions 3 and 4 on Friday night.
North West Motorway Police tweeted a CCTV image of the mob and wrote: "This pic shows approx 30 youths on a mway bridge throwing bottles at roadworkers and into the cway #whereareyourkids".
According to Manchester Evening News, a Greater Manchester Police spokeswoman said the gang had left by the time officers arrived.
Luckily no injuries were reported but police has urged anyone with information to call them on 101.
In 2012, mindless thugs put innocent passengers' lives at risk and caused a "blinding explosion" when they pushed a bike onto tracks in front of an oncoming passenger train.
The collision sent sparks flying as the bike hit the electric live rail - and the scene was caught on camera at the level crossing at Bedhampton station in Hampshire.
Inspector Mick Morriss said: "CCTV captured two youths riding across the level crossing.
"Seconds later, out of shot, one of the bikes is pushed back towards the crossing - we believe deliberately - landing on the tracks.
"I simply cannot over-emphasise enough the dangers of this type of crime. Trains travel at high speeds and there is a very real risk when they strike objects on the track that they could be derailed."
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