A sexual assault was reported in an apartment near the University of Minnesota early Monday, but the suspect was gone when police arrived and no one has been arrested, Minneapolis police said Tuesday.

A 31-year-old woman who was listed as a witness in the police report was not immediately reachable Tuesday evening. Nor was anyone else connected to the incident available for comment.

Police spokesman John Elder said a 911 call was made at 2:03 a.m. Monday from the apartment in The Knoll, a complex at 1101 University Av. SE. A police officer arrived two minutes later.

A 25-year-old woman told police she had been raped; she was taken to Hennepin County Medical Center, the report adds.

Minneapolis police are investigating. A university spokesman said the U is not investigating the case separately.