One person was shot and critically wounded in Fairfax County Friday night by a U.S. Park Police officer during a confrontation that followed a chase , the Park Police said.

The shooting occurred in the Mount Vernon/Fort Hunt area of the county, at Fort Hunt Road and Alexandria Avenue, the Park Police said.

It was not clear exactly what prompted the gunfire there. The vehicle being pursued crashed at that site, but it was not immediately known whether the crash occurred before or after the driver was shot.

The incident was traced back to another, earlier crash, which occurred about 7:30 p.m. in Alexandria, according to Sgt. James Dingeldein, a Park Police spokesman. A vehicle apparently left the scene of that crash, Dingeldein said. At some later time, police began a pursuit of a vehicle that was allegedly connected to the Alexandria crash, which occurred at the George Washington Parkway and Slater's Lane, on the northern side of the city of Alexandria.

The site of the Alexandria crash is about half a dozen miles north of where the shooting occurred, and where the pursuit ended.

Dingeldein said the person who was shot was the sole occupant of the vehicle that was pursued. He was described as male, but no age was given. .

At least part of the chase that preceded the shooting occurred on the George Washington Parkway. Fairfax County police took part in the chase, Dingeldein said.