A federal grand jury yesterday indicted four men on cocaine charges in connection with an alleged streetside drug vending operaton which District police said catered to lunch hour and evening crowds in Georgetown and on Connecticut Avenue.

Five other persons have pleaded guilty in U.S. District Court to one count of distribution of cocaine in connection with the alleged drug ring, which was the focus of an undercover police investigation last summer. Arrests were made in a surprise raid by police Sept. 28.

The four men charged by the grand jury yesterday with possession and distribution of cocaine are Alpha (Alphie) Boulos, 24, of 517 N. Piedmont St., Arlington; Geoffrey P. Lawrence, 24, of 3207 Cunningham Dr., Alexandria; Charles E. Druitt, 24, of 4501 Wetherill Rd. NW, and James Epstein, 23, of 1878 Ontario Pl. NW.

At a hearing before Judge George L. Hart yesterday, Robert R. Sizer, 21, and Shelia Hopper, 24, both of 7117 Willow Ave., Takoma Park, each pleaded guilty to one count of distribution of cocaine and were placed on two years probation.

Three others, Wayne Dresing, 27, of 4304 Queensbury Rd., Hyattsville; Joseph Lawrence, 26, of 2816 Jefferson Dr., Alexandria, and Robert S. Smethurst, 18, of 1241 31st St. NW, have also pleaded guilty in federal court to one count of distribution of cocaine.

According to law enforcement authorities, Boulos and Dresing ran the Puff and Snuff store at 1226 Wisconsin Ave. NW, where Smethurst was an employe. The Lawrence brothers and Epstein reportedly ran a vending stand at Connecticut and K NW.

Sizer was assisted by Hopper at a stand at 18th and M streets NW and Druitt was a warehouse operator at the Ontario Road address, law enforcement officials said.

It was reported in September that 2nd District gambling and vice squad detectives initiated the investigation after some vendors complained that others were involved in drug activity.