Grand Forks, N.D. ? Hundreds of volunteers lined up Tuesday to join the search for a University of North Dakota student who has been missing since Saturday. Police believe she may have been abducted.

Dru Sjodin, a 22-year-old senior in graphic arts from Pequot Lakes, Minn., was last seen late Saturday afternoon as she was leaving the Columbia Mall in Grand Forks where she worked.

Her mother, Linda Walker, said her daughter was talking to her boyfriend on her cell phone about 5 p.m. Saturday when her boyfriend heard her say, “Oh, my God.” Walker said the phone then went dead.

On Tuesday morning, the volunteers were given identification badges and assigned to teams, then bused to an area east of the city to search for Sjodin.

“I was up all night, because I’ve just been itching to get out and do this,” said Jerrod Arneson, one of the searchers. “You never think something like this would happen here, and when it does, you want to do something.”

The search was concentrated on an area around Fisher, Minn., east of Grand Forks, where police had traced a call from Sjodin’s cell phone.

Police said Sjodin’s red car, a two-door Oldsmobile Cutlass Supreme, was found in a Columbia Mall parking lot. Lt. Dennis Eggebraaten said a package that Sjodin apparently bought at the mall was inside the car.

“There was no sign of a struggle that we could determine,” he said.

Police were investigating calls to Sjodin at the Victoria’s Secret store where she worked. They said she had received at least one call from a man she did not know, who asked for her by name.

Volunteers search for Dru Sjodin along U.S. Highway 2 near Fisher, Minn. Police believe Sjodin, a University of North Dakota student, may have been abducted Saturday.