A 17-year-old Mastbaum High School student was sexually assaulted this morning as she rode the subway to her school in Kensington, said police and SEPTA officials.

The girl was on an eastbound Market-Frankford El about 7:35 a.m. when an unkempt man with a yellow t-shirt over his head approached her, grabbed her leg, and rubbed up against her, said Jerri Williams, a SEPTA spokeswoman.

The victim got off the train at the Huntingdon station and reported in the incident to school officials, Williams said.

The man is described as black, in his early 30s, about 5-foot-10, 195 pounds. He has a mustache and stubble and was wearing white t-shirt and jeans. The girl told investigators that her assailant smelled bad, Williams said.

Anyone with information is asked to call the Special Victims Unit at 215-685-3251.