Stones were thrown at a bus in Kettering by a group of children.
Northamptonshire Police have released two images of boys they would like to speak to regarding the incident.
The group of four, who were all aged between 12 and 14, threw stones and rocks at the Stagecoach bus in Jean Road at about 5.40pm on Tuesday, March 17.
After attacking the bus, one of the boys made off on a scooter to the nearby allotments.
He was white with brown hair and was wearing a grey hooded top.
One of the other boys was also white and wore a blue hooded top.
Witnesses, or anyone who recognises the people in the attached images, can call Northamptonshire Police on 101.
Alternatively, they can call the independent charity Crimestoppers anonymously on 0800 555 111 or use the anonymous online form at www.crimestoppers-uk.org.