City police have issued an alert for help identifying a man suspected of a sexual assault Saturday night in the Back Bay.

The alleged attack occurred in the area of Beacon Street and Public Alley 908, police said, at about 11:45 p.m.

The suspect is described as a possibly Middle Eastern male, 5’8” – 5’10”, medium to heavy build, with dark curly hair and facial hair, wearing a navy-blue shirt with tie-dye design and black baggy sweatpants with two (2) white stripes. The suspect reportedly spoke English with an accent and also spoke in another language.

The Boston Police Sexual Assault Unit is actively reviewing the facts and circumstances surrounding this incident. Anyone with any information is asked to call detectives directly at (617) 343-4400.