YOBS smashed a glass door on a bus as it travelled through Hartlepool with passengers on board.
The bus was travelling along Eskdale Road in Hartlepool when three boys walked towards the vehicle and threw stones at the door, causing the window to shatter and the driver to perform an emergency stop.
Police are appealing for information on the attack, happened on Thursday, January 31, at 3.40pm.
The youths are described as white, aged 10 to 12-years-old, around 4ft 10in-tall, with brown hair, and wearing dark school blazers with one of them wearing grey trousers.
Anyone with information is asked to contact PC Andrew Morland of Hartlepool Police Office on 101 or call the charity Crimestoppers anonymously on 0800 555 111.