A worker was left temporarily blinded after a laser light was shone in his eyes at a controversial HS2 construction site.
Thames Valley Police said it is appealing for witnesses after the man, in his 50s, was left blinded for 15 minutes and in need of hospital treatment.
The incident took place on Wednesday afternoon at the HS2 construction site in Wendover, Buckinghamshire, where campaigners have been battling against the felling of woodland for the high-speed rail link.
Thames Valley Police said the man was standing next to an HGV in Jones Barn Farm Hill when it is believed a green laser was shone towards him.
The force said: "He turned towards the light source, which then went into both of his eyes, causing his vision to be impaired and prevented him from working.
"His eyesight remained impaired and blurred for 15 minutes, and he has since suffered pain in his eyes.
"The victim has received hospital treatment since."
Two other people in the area also noted they had a laser shone at them, police said, but they did not suffer any blurred vision or injury.
A Thames Valley Police spokesperson said: "This incident was a dangerous act, which resulted in a man aged in his fifties sustaining blurred vision and also pain in his eyes."
The force urged anyone with any information to come forward by calling 101 and quoting 43210192922, or by making a report online or calling Crimestoppers anonymously on 0800 555 111.
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