There was no immediate official word on details of the shooting or on the condition of the victims.
An eyewitness told local television station WUSA-TV he heard a burst of rapid gunfire lasting about a minute, and saw one woman running out of a building who appeared to have been grazed by a gunshot, followed by other individuals who were apparently wounded.
The eyewitness said he saw other people on the street taking cover behind parked cars and pointing up to a balcony where they presumably believed the gunshots originated.
Police said on Twitter that two male victims and one female victim were located at the scene, but their conditions were not described.
District of Columbia police urged residents in the vicinity of the shooting to shelter in place, and advised that a large law enforcement presence was in the area.
According the District of Columbia’s Metropolitan Police Department, the shooting unfolded in 4100 block of Connecticut Avenue in the city’s northwest quadrant, an area that local media said was near the Edmund Burke School, a private college preparatory academy.
The University of the District of Columbia, which is also nearby, said on Twitter its Van Ness campus was on lockdown.