A 17-year-old Wheaton youth died yesterday after being shot Friday night by an off-duty Montgomery County police officer who police say was trying to break up a fight among a crowd of teen-agers when the youth turned on him with a baseball bat.

Police said David Anthony Bane, who lived at 3316 Camden St. in Wheaton, was shot late Friday night by Officer Michael J. Jones, a 19-year member of the force, and died yesterday afternoon at Suburban Hospital after undergoing surgery for a bullet wound to the chest.

Jones, according to police, was driving past Aspen Hill Road and Connecticut Avenue in north Wheaton shortly before 11:30 p.m. Friday when he saw about 60 teen-agers gathered in the lot of a gasoline station. Police said that Jones saw some of the youths fighting and attacking each other with clubs, sticks and baseball bats, and that Jones tried to intervene.

"Officer Jones went to the crowd holding his badge up and identified himself as a police officer," said Officer George Ludington, a police department spokesman. "At one point, he confronted a 17-year-old youth holding a baseball bat. Officer Jones identified himself as a police officer and told the youth to drop the bat several times. And the youth came at the officer with a bat."

Ludington said Jones fired one shot and that the bullet hit Bane in his left arm, then entered his chest.

Police said five other juveniles were arrested after some in the crowd turned on the officer after the shooting. The youths were charged with a range of offenses, including hindering the investigation, disorderly conduct, and assault and battery.

The Wheaton shooting was the second time in about two weeks that an off-duty Montgomery County police officer has been involved in a shooting death. Last month, Officer Harold K. Allen, a three-year member of the force who was moonlighting as a security guard, fatally shot a Germantown man during a parking lot confrontation at a Gaithersburg hotel.

Allen said he fired his revolver twice after being threatened with a flashlight. He has been placed on administrative leave with pay pending a department investigation.

Ludington said Jones has also been placed on administrative leave with pay pending an investigation of Friday night's shooting.

"The kid came after the officer," said Ludington, who said that Jones had repeatedly yelled at the crowd that he was a police officer.

When the crowd turned on Jones after the shooting, Ludington said, several people who witnessed the attack came to the officer's aid, and Jones asked one of them to call for additional police assistance.

Shortly after the shooting, Ludington said, another off-duty officer, who was also a paramedic, noticed the crowd while driving past the gas station and stopped. But when the officer tried to help the injured youth, Ludington said, "he was physically blocked by four or five unknown teen-agers."

Bane was later taken to Suburban Hospital by an ambulance, police said.

One teen-ager who knew Bane but did not witness the shooting said that the youth was a student at Wheaton High School and that the shopping center at the intersection was a popular weekend hangout for high school students.

Under county policy, police officers are obligated to respond to any sign of crime or trouble they may encounter while off duty.

After the Gaithersburg shooting last month, a police spokesman said department policy allows an officer to shoot in defense "for what he perceives to be an immediate threat of death or serious bodily injury."

Warning shots are not allowed, he said. If an officer decides to shoot, he is shooting to kill.Staff writer Patricia Davis contributed to this report.