Bus surveillance photographs of a man suspected of sexually assaulting a woman late one night over the weekend in Minneapolis were released to the public Wednesday by police.

The attack on the 33-year-old woman occurred shortly after 2 a.m. Saturday and was the third sexual assault by a stranger on a woman walking alone at night in Minneapolis in the past three weeks.

The latest attack was near 34th Street and Chicago Avenue S., close to where she had gotten off the Route 5B bus from downtown Minneapolis on her way home, police said.

The series of photos show a man appearing to board a bus. Police describe him as black, 30 to 40 years old, with a thin mustache and possibly a goatee. He was wearing a skull or knit cap with a light-colored design band around it and a dark-colored puffy jacket.

A friend of the woman said Tuesday that the man stalked the woman after she left a downtown bar, got on the same bus and then got off at the same Powderhorn Park stop as she did. Sheila Gustafson said her friend told of being dragged to a fenced-in area near a day-care facility and sexually assaulted.

Crime Stoppers of Minnesota is offering a reward of up to $1,000 for information about the case. People can call 1-800-222-8477 with tips.