Three teenagers were arrested after a cricket ball was thrown through a bus window injuring an elderly woman and a baby.
The incident happened just before 2pm as the bus was travelling along Cass House Road, Hemlington in Middlesbrough.
The ball shattered the window on the bus, striking 74 year old Dorothy Simpson above her left eye and showering Mandy Burns and her four children with glass.
Mrs Simpson, who was taken to James Cook University Hospital for treatment, suffered a large bump on her head and bruising and swelling around her eyes.
Mandy and her 16 month old daughter Lily suffered minor cuts to their fingers but her other daughters escaped without any injury.
Detective Constable Nick See said “This was clearly an alarming and distressing experience for all the passengers on the bus, especially those injured.
“This was an act of mindless vandalism and a great danger to anyone using that road. The consequences could have been far more serious.”
The bus company, Stagecoach North East, have put measures in place in an attempt to deter such incidents from taking place.
Over 50% of their vehicles have external and internal CCTV fitted and the company are making every effort to ensure that all their vehicles have the same technology fitted by the year 2011. The youths aged from 15 to 16 years old were subsequently released on bail while police made further inquiries.
Police are appealing for anyone who witnessed the incident or who have any information to contact Detective Sergeant John Wrintmore of Middlesbrough CID on 01642 303126.