The incident had caused damage to at least three vehicles.
According to Kota Setar police Chief, ACP Mohd Rozi Jidin, police took statements from three victims, aged between 31 and 42, who all lodged police reports on the same night.
Investigations were underway to track down the suspects, he added.
In their reports, the victims claimed the rocks were thrown from a bridge at KM40.6 of the PLUS highway (northbound) between Jitra and Bukit Pinang between 10.30pm and 10.45pm.
The vehicles damaged in the incident were a Mazda which suffered a cracked roof and windscreen; a Mitsubishi Triton, impaired at the bonnet, windscreen and front bumper, and a Toyota Vios, which had its front lights busted and front bumper dented.
The Mazda was driven by a woman while the other two vehicle had male drivers. The female victim had posted about the incident on her Facebook last Friday.
She had also proposed for the highway concessionaire to install a CCTV at each bridge to avoid such incidents from recurring.
She had also proposed for the highway concessionaire to install a CCTV at each bridge to avoid such incidents from recurring.
Meanwhile, the police's initial investigations revealed that two large rocks were thrown from the bridge.
Checks also showed that this was the first such case reported this year.
The case is being investigated under Section 427 of the Penal Code for committing mischief.
Checks also showed that this was the first such case reported this year.
The case is being investigated under Section 427 of the Penal Code for committing mischief.
