An off-duty uniformed officer with the U.S. Secret Service was fatally shot early yesterday morning during a robbery as he left a Northwest Washington bar.

George Irving Coaxum, 32, a 9-1/2-year police veteran, was shot several times in the neck and head outside Chuck's Bar and Grill, 1432 Irving St. NW., about 2:30 a.m. His wallet and service revolver were taken.

Nine hours later, D.C. police arrested two men and charged them with murder in Coaxum's death. His revolver and the weapon used in the murder were recovered, police said.

Police said interviews of witnesses and people in the area of the bar led them to the arrests. One of the two men was arrested in an apartment building around the corner from the bar.

Chuck Gary, owner of the bar, said Coaxum came to the bar earlier in the evening with "some other people." He had "a couple of drinks," which he paid for with a $10 bill.

There was a report that Coaxum had talked with another person in the bar who had tried to strip him of his service revolver, but police said they had been unable to confirm that report.

Gary said the bar closed at 2 a.m., and that Coaxum and about a dozen other people left at that time.

About a half hour later, Coaxum was found lying on the sidewalk outside of the bar. His pants pockets had been turned inside out and his gun and identification were missing.

For several hours, police were unable to identify the policeman. But, according to one report, police found a call key in a nearby alley and traced it to Coaxum. Call keys are used by policemen to open telephone boxes along city streets from which they can call their office.

After interviewing several witnesses, police obtained arrest warrants for John Vincent Coates, 24, of 315 50th St., NE, and Sheldon Roger Ford, 26, of 3237 Hiatt Pl. NW.

Coates, who is employed as a street cleaner, was arrested in a car at Brentwood and W streets NE. Ford was arrested in an apartment at 1401 Columbia Rd. NW.

According to the owner of the bar, the two men arrested are regular customers there. However, it was unclear if they had been in the bar before the shooting.

Gary said he opened the bar, which features go-go dancers, about six years ago. He had previously owned two bars, one at 14th and Harvard streets NW, and the other at 14th and Girard streets NW.

Gary, who was not in the bar when Coaxum was there, but had been told about the incident by his night bartender, said Coaxum had not been in the bar before Thursday night. But, others said Coaxum had been there before.

A Secret Service spokesman said Coaxum, of 6701 14th St. NW, had two children, ages 12 and 13. His wife, Nora Coaxum, a metropolitan police officer assigned to the 6th District, said she and her husband had been separated for more than a year.

A native of Colleton County, S.C., Coaxum joined the Secret Service in July 1970. He was assigned to the foreign mission division of the U.S. Secret Service, which is responsible for guarding foreign embassies.

A Secret Service spokesman said Coaxum had worked the day shift on Thursday on patrol duty, moving between various embassies.

According to the spokesman, members of the uniformed division of the Secret Service are authorized, but not required, to carry their service revolvers while off duty.