Bus passengers in a Devon resort were shocked as a large gang of youths pelted their vehicle with rocks and stones.
The Stagecoach double-decker 34 service was in Sovereign Mews, in Watcombe, Torquay, when it was attacked.
Police said when the driver stopped the bus near the King George V playing fields on Thursday, the group of between 10 to 15 youths ran off.
Three windscreens were shattered by the rocks, but no-one was hurt.
The cost of the damage to the bus is estimated at £5,000.
A Stagecoach spokeswoman said it is the second attack on one of their buses in the same area.
She said drivers are given "social inclusion and behaviour" training which includes how to deal with this type of incident.
"The driver did absolutely everything right last night," she said.
"Fortunately nobody was injured, but this was a mindless act of vandalism which could have led something potentially much more serious."
Anyone with information about the attack, which happened at about 2045 BST has been asked to contact police.