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.

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 to contact authorities.