Arlington police who arrested three men and a juvenile yesterday after an early morning armed robbery at a McLean 7-Eleven store said that one of the suspects had been shot, apparently with a gun used in the robbery.

Police said a man with a shotgun and two others armed with handguns entered the 7-Eleven store at 8110 Old Dominion Dr. at about 4 a.m. and forced the manager to give them an undetermined amount of money.

Fairfax police who went to the scene radioed area police to look out for the suspects. A short time later, Arlington police stopped a car with four occupants near the 14th Street Bridge.

Police said that James Tyron Clark, 23, of 1905 Frederick Pl. SE in the District of Columbia, a passenger in the car, was suffering from a shotgun wound in the buttocks and was transported to Arlington Hospital. He was reported in good condition yesterday.

Clark, Gilbert Michael Powell, 22, Anthony N. Ferebee, 19, of 3460 22nd St. SE, and an unnamed juvenile were charged with possession of a sawedoff shotgun by Arlington authorities and armed robbery by Fairfax authorities.

Clark remained in the hospital yesterday.Powell, who gave no fixed address, and Ferebee were held in the Arlington Detention Center on $10,000 bond. The juvenile was turned over to juvenile authorities.