More than 12 incidents of people throwing stones and bricks at buses in Northamptonshire have been reported in the last few weeks.
Police are now investigating the spate of incidents during which buses in Kettering have been attacked by bricks and stones.
Since December 4, at least 12 incidents have been reported, having occurred in the early evenings and in the London Road area or surrounding roads.
The most recent incident was on Saturday, January 31 at around 5.30pm when a brick was thrown at the offside, rear window of a bus travelling on Pytchley Road, causing the window to smash.
A number of buses have been damaged as a result of the incidents.
In some of the cases a group of between three and five teenagers have been seen in the area.
Officers are stressing the dangers of throwing objects at any type of vehicle and the potential risk to the drivers, passengers and even pedestrians, caused by these offences.
Anyone with any information can call Northamptonshire Police on 101 or Crimestoppers confidentially on 0800 555111.