An Alexandria youth was shot Friday night when a spectator opened fire on a crowd of teen-agers watching a street fight that stemmed from an earlier altercation at a dance at Groveton High School, Fairfax County police said.

Eric E. Roy, 17, a junior at Alexandria's T.C. Williams High School, was hit in the upper chest by a .38-caliber bullet, police said. He was listed in good condition at Alexandria Hospital yesterday, hospital officials said.

Police could not say whether the shooting or a fight that erupted at the dance were related to tensions that brewed in the area for several months this winter when the School Board was considering closing Groveton High.

"It's my understanding that it had absolutely nothing to do with tensions on the school closing," said T. Farrell Egge, a member of the Fairfax County Board of Supervisors.

In a phone interview from his hospital bed yesterday, Roy said he and a friend had been walking to their car from the Beacon Mall Theatres, where they tried to get tickets to "Friday the 13th."

"I just saw people running," Roy said, adding that he heard a gunshot. "I just ran too to get out of the way." When he got into the car, he said, "I felt pressure on my heart and there was blood on my hands." His friend drove him to Alexandria Hospital, he said. Police said he underwent surgery to remove the bullet.

Police said that shortly after 11 p.m. Friday a large crowd gathered at the intersection of Richmond Highway and Beacon Hill Road "to continue an altercation" that began earlier at the school.

They said Roy was among those watching as a person was assaulted "with sticks and chains." From across the street another person "drew a pistol, fired and struck Roy," a police spokesman said. Roy said he did not see people fighting.

Police said the gunman, believed to be 17 or 18 years old, fled through the Beacon Mall Shopping Center and into the Beacon Hill apartment complex. Police dogs searched for the suspect, but he was not located, police reported. No one was able to identify him, police said.

Fairfax County police also another incident earlier during the dance at Groveton. They said that about an hour before Roy was shot, there was an altercation and a juvenile was arrested and charged with disorderly conduct. He was released to the custody of his parents, police said.

On March 14 the Fairfax County School Board decided to keep Groveton open and to close nearby Fort Hunt High School.