According to hospital sources, one person died on the spot, the second on arrival at the hospital, and the third died in the operating room.
Another person is reportedly in critical condition.
Shooting of six men and three women happened about 7:30 pm in south-eastern Washington DC , police Department spokesman Officer Hugh Carew told an international news agency.
According to the fire department spokesperson all the victims were in their twenties and thirties, barring one teenager.
In the pursuit of the suspects vehicle, four police officers also received minor injuries.
Even though three people have been nabbed and the weapon recovered, the motive behind the shooting is yet to be ascertained.