Several people armed with BB guns fired into a crowd of teenagers in Loudoun County on Halloween night, injuring a 14-year-old girl, another victim in a series of BB shootings in Northern Virginia, officials said yesterday.

Police don't believe the shooting, in which the girl was hit between the nose and an eye and taken to an emergency room, is related to other recent shootings in Arlington County, Alexandria and Manassas.

A pedestrian was shot in the leg, two businesses were damaged and dozens of car windows were shattered in separate incidents last week.

In the latest shooting, a 10-year-old boy was hit in the head by a BB while playing in his Alexandria yard about 8 last night, police said. He was not seriously injured.

The Sterling attack came as the American Academy of Pediatrics released a report yesterday that highlights the dangers of BB guns and other weapons -- pellet guns, air rifles and paintball guns -- that use compressed air instead of gunpowder to launch projectiles.

The report says such guns killed 39 people nationwide, including 32 children 15 and younger, between 1990 and 2000. In 2000, nearly 22,000 injuries related to such guns required treatment in emergency rooms. BB guns and other such guns, the report says, are nearly as powerful in velocity as traditional firearms.

"The prevailing cultural attitude is that these guns are toys, but they can be used as weapons and they can be absolutely lethal," Denise Dowd, an emergency room doctor in Kansas City, Mo., said.

"If they're fired at close range, they can penetrate the skull and the brain, go through the abdominal wall, collapse someone's lung or perforate their bowels."

In Sterling, the 14-year-old girl had been standing with a group of about 20 friends near a house on Kentwell Place near Woodmere Court, law enforcement officials said. About 8:30 p.m., BBs suddenly started flying at the teenagers, possibly from a nearby wooded area. The teenagers were not trick-or-treating.

Struck on the neck, arms and face, the teenagers began running inside, said Loudoun County Sheriff's spokesman Kraig Troxell. The 14-year-old was cut near her eye and treated at Loudoun Hospital and released. No one else in the group was injured severely enough to require hospitalization, Troxell said.

He said investigators have several suspects, including as many as four teenagers who might have been wearing black clothing.

Several of the victims attend River Bend Middle School, and authorities are working with officials there and at nearby Potomac Falls High School to solve the case.

The Sterling attack followed by less than one week a series of other shootings with BB guns.

In Arlington, a man walking on Wilson Boulevard was shot in the leg with a BB gun last Tuesday night, police said. The same night, the windows of at least nine parked cars were shot out, they said.

About 35 cars were damaged in Manassas during a three-day period last week, police said. In Alexandria, 19 cars parked in the Jordan Street corridor were damaged on Wednesday night, as was a skateboard shop in the 2700 block of Duke Street and a dental office in the 3600 block of King Street, police said.

Troxell said investigators don't see any relationship between the Loudoun assault and the earlier shootings. "It's just coincidence," he said. "These things happen in cycles."

Investigators in Arlington, Manassas and Alexandria echoed that view and said they've see no more BB gun incidents since last week and no general upsurge.

"BB guns are not new to us," said Alexandria police spokeswoman Amy Bertsch, who said the guns are used occasionally in assaults and robberies.

But authorities sharpened their warnings yesterday about the dangers of BB and other such guns.

The Loudoun sheriff's office even included a Web link to the American Academy of Pediatrics report in its news release on the Halloween night shooting.

"This sends out an important message to parents that these are weapons, they can be dangerous and they can cause injuries not only like the one this girl suffered but also fatal injuries," Troxell said. "These are not toys.''