Cambridge Police report roving fights between two groups of men in several locations around Harvard Square ended with an 18-year-old man getting shot in the area of Eliot and JFK streets around 3:30 a.m.
Police say the wounded man, who is expected to recover, did not wait around for them; he got himself to a nearby hospital.
Officers recovered several shell casings on Eliot Street.
Police added that as part of the investigation into the shooting, officers arrested a 27-year-old Roxbury man on a charge of distribution of marijuana.
Anyone with information about the shooting or the fights that preceded it can call police at 617-349-3300 or contact the anonymous tip line by calling 617-349-3359 or texting a message, starting with TIP650, to 847411.