Ashland, Va. ? A 37-year-old man was shot and wounded Saturday night in a steakhouse parking lot, and authorities were investigating whether the Washington-area sniper had struck again, for the first time on a weekend.

The victim was walking through the parking lot of a Ponderosa restaurant with his wife when he was shot once in the abdomen, authorities said. He was rushed to a hospital and was undergoing surgery.

Some witnesses said they heard the shot coming from a wooded area at the edge of the parking lot, said Ashland Police Chief Frederic Pleasants. He said no bullet had been recovered and no one saw the shooter.

State police spokeswoman Corinne Geller said portions of Interstate 95 were immediately shut down as police set up road blocks. She said it was too early to tell if the shooting was related to the Washington-area sniper.

Maryland State Police Sgt. William Vogt said troopers were on the lookout for a white van with a ladder rack. A sniper task force was on its way to the scene, said Montgomery County police Capt. Nancy Demme.

Pleasants said there was an early report of a white van near the shooting. He said the Hanover County Sheriff’s Office had stopped a white Econoline van on an Interstate 95 on-ramp shortly after the shooting, but let the driver go.

Ashland is about 90 miles south of Washington and about 35 miles south of Fredericksburg, where two previous shootings this month were linked to the sniper.

If the shooting turns out to be related, it would be the first time the sniper attacked on a weekend; it also would follow the longest lull in between shootings as the break in the spree had stretched into a fifth day.

It would also be the 12th sniper shooting since they began Oct. 2; nine of the victims were killed. Before Monday’s killing of FBI analyst Linda Franklin at a Fairfax County Home Depot store, the longest gap between shootings was three days.

Pleasants said the victim and his wife were walking to a car in the parking lot behind the restaurant about 8 p.m. when he was shot. The victim’s wife heard a sound, but didn’t recognize it as a gunshot, then saw her husband take about three steps before collapsing, Pleasants said.