A weekend outing by four Northern Virginia teen-agers ended in tragedy when they and two other people were killed in a head-on collision with an allegedly drunk driver on a winding road near the West Virginia border.

The four had gone to the small town of Gore, Va., to celebrate the birthday of a friend who had moved there several years ago from Herndon. The friend and a woman relative of one of the teen-agers were among those killed in the collision Saturday night.

"It's been a real tragedy because all the families knew each other," said Dru Mentzer, whose 19-year-old brother, Tracy, of Herndon, was among the victims. "They were all good friends."

It was to have been Lottie Bays' birthday. Accounts differ as to whether she was to have been 16 or 17 years old, but all agree she had gone with her friends to a restaurant in the Gore area and died as they were returning to her home. Also killed was Janice Bays, 53, identified as either the girl's mother or grandmother.

Three of the teen-age visitors who perished in the collision came from Herndon. In addition to Mentzer, they were Sandy Wheeler, 19, and Barbara E. Thomas, 17. The sixth victim was Tim Boyd, 19, of Sterling.

According to police, the accident occurred about 10 p.m. on Rte. 259 near the West Virginia border. Police said a car driven by Daniel Chafin, 22, of Peterstown, W.Va., was heading north at high speed when the driver apparently lost control and collided head-on with the car in which Bays and her friends were riding.

Chafin, who was hospitalized after the accident with a broken left leg, was charged by Virginia police with driving under the influence of alcohol. West Virginia police charged him with unauthorized use of a motor vehicle and grand larceny in connection with a shotgun and a rifle found in the car.

The accident followed an automobile chase in which Chafin was pursued by Wardensville, W.Va., Police Chief Richard Jenks, police said. The car Chafin was driving had been reported stolen. Jenks reportedly ended his pursuit after Chafin crossed into Virginia.