The attack happened Saturday night in Potiskum, a town in Yobe state. Officials told an Associated Press journalist that the doctors worked at the General Hospital in Potiskum.
The AP journalist saw the dead in the hospital morgue. One had been beheaded in the attack.
The three routinely traveled alone and without security guards in the city, which has been a repeated target of a radical Islamic sect known as Boko Haram. A Nigerian police official confirmed the attack took place, but declined to immediately comment further.