"Attacks are mostly confined to the use of spray paint or fireworks," revealed Chief Inspector Christopher Moorehouse-Everett.
"However, there were one or two roads on which cameras have been repeatedly set ablaze. And as soon as we install a replacement unit, the new one is also set alight."
West Yorkshire is the first force to install the new spy cameras, which have night vision and are directly linked to their CCTV monitoring station. Other regions are watching the results and may follow suit. The surveillance unit is hidden at a safe distance on street lamps or road signs.
Alarms, fitted around the speed cameras, are triggered if anyone tries to tamper with them, but they re-main silent to the attacker.
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