More than 1,500 commuters on the VRE commuter line in Virginia were delayed for more than an hour Wednesday evening after investigators unearthed a spooky discovery near the tracks: a box filled with what may be human remains.

The box was discovered near the tracks at the Manassas Park station at about 6 p.m., said Mark Roeber, a VRE spokesman. He said the box appeared to contain human remains, but no details were immediately available. Local police stalled traffic as they set up a crime scene to figure out just what had been deposited there.

The investigation snarled the commute for four trains running along the line during rush hour. Roeber said at about 8 p.m. that the transit system was backing three trains into stations in Alexandria, Burke and Clifton. Riders were then to board buses or a Metro train to reach their final destination.