CHARLOTTESVILLE, Va. >> Nearly 1,000 volunteers, some driven by worry for the safety of their own families, fanned out from the University of Virginia campus Saturday to search for a sophomore who disappeared a week ago.

Volunteers met at the university’s basketball arena before going out in teams throughout Charlottesville to search for 18-year-old Hannah Graham.

“I have two daughters of my own and I would hope that if one of them was missing, everyone would come out as well,” said Marci Stewart, a volunteer searcher.

Police said Friday they have spoken with a man they believe was with her in a bar on the night she went missing, but did not have enough information to arrest or detain him after searching his car and apartment.

In an emotional appeal, Charlottesville Police Chief Timothy Longo asked anyone who might have seen Graham and the man early Sept. 13 on the Downtown Mall to contact authorities. Longo stopped short of calling the unidentified man a suspect, but said police are keeping an eye on him.

Police have focused on Graham’s movements the night of Sept. 12 and into the early morning hours of Sept. 13. The sophomore from northern Virginia met friends at a restaurant for dinner, stopped by two parties at off-campus housing units, and left the second party alone, police have said.

Surveillance videos showed her walking, and at some points running, past a pub and a service station and then onto the Downtown Mall, a seven-block pedestrian strip lined with shops and restaurants.

Graham’s disappearance has sent a ripple of fear through the quiet college town.

Maria Faidas, a sophomore who volunteered to help search Saturday, said she lives a block from Graham and has walked home alone before without thinking twice of the possible dangers.

“It’s definitely a wake-up call, I think, because I always felt safe,” she said.

Students said they’ve started walking in pairs at night and are paying closer attention to their surroundings.

At least three other young women have disappeared in the area in the last five years. Nineteen-year-old Samantha Ann Clarke, who vanished after leaving her Orange County town house in September 2010, and 19-year-old DaShad Laquinn Smith, who disappeared in Charlottesville in November 2012, remain missing.

Morgan Harrington, a 20-year-old Virginia Tech student, disappeared from the University of Virginia’s John Paul Jones Arena while attending a rock concert in October 2009. Her remains were found three months later in a rural area. No arrests have been made.

Police have said they do not think Graham’s disappearance is linked to any of the other missing women.

Emily Kilroy, a consultant who also helped search, said the episodes are “starting to feel like a pattern” that’s especially unfortunate in a college town with so many young women.

“They should be made to feel safe,” she said.

Virginia Department of Emergency Management spokeswoman Dawn Eischen said there were 981 volunteer searchers as well as 100 others who had search-and-rescue training. She said the search would continue Sunday.