Police in Maryland and Virginia are investigating alleged sexual abuse of boys as young as 8 by a group of men in Montgomery County, Fairfax County and Alexandria.

Two men have been arrested in the case and more arrests are expected, according to Detectives Gary Costello and Richard Cage of the Montgomery County Police Department.

They said yesterday that they believe the group has been active for five or six years.

"It is an operation that reaches into Washington, and perhaps beyond Washington into other parts of the country," said Costello.

Arrested and charged with child abuse and sex offenses are Richard Elwood Shockley, 42, of 19023 Mills Choice Rd., Gaithersburg, and Ronald Stephen Kemp, 28, of 823 Quince Orchard Blvd., Gaithersburg.

Kemp is a salesman who has been a baseball coach with the Montgomery County recreation department, police said. They said that Shockley, who listed his occupation as a marketing consultant, participated until 1981 in the county-sponsored Pal organization, which pairs adult men with boys who need attention and friendship.

The investigation began when a Montgomery County mother telephoned to report her concern about some remarks that her 13-year-old son had made about his relationship with Kemp, police said. They said that the investigation of Kemp led them to other boys, one of whom allegedly had been victimized by Kemp and Shockley.

When police searched Shockley's apartment, they found sexual paraphernalia, letters describing sexual encounters and about 200 photographs, some of which depicted men and boys engaged in sexual activity.