PORTLAND, Ore. (KOIN) – An unidentified man who allegedly groped a teenager’s breasts at a Southeast Portland bus stop remains at large, police said.

Around 8:45 a.m. Monday, the 15-year-old girl was waiting at the corner of Cesar E. Chavez and Powell Boulevard when the man walked toward her and spoke in sexually explicit terms, officials said. Then he grabbed the girl and groped her breasts.

The girl screamed and tried but was not able to get away, police said. Then someone driving by noticed the girl was in distress, stopped and helped her escape before driving her to where she wanted to go.

Police looked for the man in the area but were not able to find him.

The suspect is a “white man with tan skin,” about 5-feet-8, silver hair and a short gray beard. He was wearing baggy gray clothes and carried 2 black trash bags, authorities said.

Authorities would also like to talk with the driver who stopped and helped the teen.

The investigation is ongoing. Anyone with additional information is urged to call PPB at 503.823.3333, or email police at crimetips@police.portlandoregon.gov