A 14-year-old girl was molested on her way to school in Worthing, police have said.
Sussex Police said the girl was walking along a footpath between Barrington Road and Elgin Road at 0830 GMT on Monday when she was targeted.
Officers said a man walked up behind her, touched her hair, put his arms around her and touched her sexually.
Det Sgt Alex Lowe said it was an isolated incident and the girl was shaken but unhurt.
The suspect was in his 40s and was wearing a red T-shirt, blue jeans and brown boots.
Police have stepped up patrols in the area and are talking to schools to ensure pupils receive safety advice. They are appealing for witnesses.