A teenage girl was sexually assaulted on her way home from school on Friday.
A man sat next to the girl on the lower deck of the 4.13pm bus from Sutton to Banstead before sexually assaulting her.
The man was Asian, in his 40s, and was wearing a sandy coloured woolly jumper.
He was about 5ft 9in, with a large build, unshaven and had short black cropped hair.
Anyone with information should call Surrey Police on 101 quoting reference RB/13/1458 or call Crimestoppers anonymously on 0800 555 111.