Vandals are being hunted by police after attacking five buses serving a Sheffield estate.
Yobs hurled missiles at the buses, all operated by bus company First, as they travelled along Monteney Road in Ecclesfield on Monday night.
Bus bosses were forced to withdraw the damaged vehicles from service for emergency repairs to be carried out.
A total of eight smashed windows needed to be replaced before the buses could travel again.
None of the drivers or passengers on board the buses at the time was injured.
But Duncan McGraw, spokesman for First in South Yorkshire, said: “Such behaviour cannot be tolerated.”
He confirmed: “On Monday night we had a number of reported anti-social incidents in the Monteney Road area of Ecclesfield.
“This meant we had to divert a number of services to ensure the safety of our customers and vehicles.
“There were no reported injuries and we would like to apologise to any customers inconvenienced.
“We are working with South Yorkshire Police and the local authorities to tackle the root causes of these types of incidents, as such behaviour cannot be tolerated.
“We would urge anyone who knows anything about the anti-social behaviour to contact the police immediately.”
Earlier this month, in the space of 90 minutes, four First buses were vandalised in another wrecking spree on the same city estate.
Bosses had to suspend services then to avoid Monteney Road, Morrall Road and Yew Lane.
Each incident has been reported to South Yorkshire Police and an investigation is now under way.
CCTV footage captured by onboard cameras is being examined.
Witnesses to any of the vandalism attacks, or anyone with information on the culprits responsible, should call South Yorkshire Police on 101 or Crimestoppers, anonymously, on 0800 555 111.