Police have confirmed a woman was injured after youths threw a brick at a bus in Northolt.
Officers were flagged down in Horse Shoe Crescent at around 7.20pm on March 14 after the brick had hit the door of a bus and shattered the glass.
The bus driver stopped immediately and a female passenger fell to the ground and was injured as a result of the vehicle braking hard.
A Metropolitan Police spokesman said: "Officers went to the assistance of the injured woman and, during this time, youths threw two small stones at the bus.
"Officers searched the area but found no suspects.
"The female was subsequently taken to hospital with back pain."
Mike Roberts, who lives in the area, heard about the incident from a friend.
He told getwestlondon: "There was a number two bus travelling down the Kensington Road [in Northolt], by the Smith Farm Estate, and someone threw a brick into the bus.
"The brick smashed the window of the bus and the driver put on his brakes."
He said the woman was lying unconscious by the side of the bus until the ambulance arrived.
Mr Roberts added: "She was discharged from hospital but she's still at home with severe bruising."
Enquiries are ongoing. Anyone with any information is asked to contact 101 or Crimestoppers, anonymously, on 0800 555 111 quoting crime reference 2506445/15.