An 11-year-old girl was injured and a passenger got glass in their eye after a stone was thrown at a bus in West Drayton .
Police are investigating the incident which happened just before 3.21pm on Friday July 21.
The Metropolitan Police said a stone was thrown at a passing U3 bus as it travelled southbound along Wise Lane in West Drayton.
A spokesman for the police said: "The window nearest to the drivers' cabin shattered and the stone hit the back of an 11-year-old girl's head.
"A second victim got glass in her eye from the damaged window.
"Officers took the girl to a west London hospital and she was later discharged.
"The second victim got off the bus and was not seen since the incident."
PC Juliet Toll, the officer in the case from the Hillingdon Safer Transport Team, said: "It is lucky that this incident did not result in something more serious, like the victims being more seriously injured, or a broken window causing the bus to have an accident.
"So we take incidents of this nature seriously.
"So we are appealing for anyone who witnessed the incident to come forward.
"Did you see anyone throw something towards the bus?
"Did you see anyone running away after the window broke?
"If you did, please contact me and assist our investigation.
She added: "We are also appealing for the second victim with the eye injury to come forward, as we would like to ensure she is safe and well and get her account of what happened.
"She was described as a black woman aged in her 50s carrying a black suitcase."
Any witnesses, or anyone with any information, is asked to contact PC Toll at Hillingdon Safer Transport Team via 101, or via Twitter @MetCC, or to Crimestoppers anonymously on 0800 555 111.
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