A Washington police officer, Nathaniel Coates, 38, was charged with assault with a deadly weapon yesterday morning after a fellow officer was shot in the leg, police said. Both officers were off duty at the time, police added.

Officer Ronald Wallace, 37, was shot in the left leg while he was sitting in a car near 16th and Newton streets NW shortly before 6 a.m. yesterday, according to a police spokesman.

The spokesman said the shooting was the outcome of "an apparent personal argument" between Wallace and Coates.

Both men are assigned to the 4th Police District, which includes parts of Adams-Morgan and Mount Pleasant.

Wallace, who has been with the force since 1975, was listed in fair condition last night at Washington Hospital Center for treatment of the bullet wound.

Police said a woman who was with the officers at the time of the incident is serving as a witness. Her name was not released.

A police spokesman said last night that Coates' service revolver was used in the shooting.

Coates, a member of the police force since 1968, was released yesterday on $2,000 bond and has been placed on administrative leave pending an investigation, police said.