A UFO stopped in its path and hovered. It then trailed an airplane.My mother went into a store to pick something up. We were at the top of a street. I could see partially over the Delaware River. I saw a sinlge object with one light in the distance travleing unuaually slow from the west.It was traveling very smoothly, as if gliding through the air. I then saw an airplane traveling at normal speeds comming from the east. They were very close in paths and it looked like they could possibly collide. I could see the airplane ascend as if to get more air space. The UFO went straight, it did not ascend or descend. The plane went over the object. The object then stopped and hovered for about 5 to 7 seconds. It then seemed to trail the plane but could not keep up. The plane was no longer in my sight. The UFO then flew off to the west(in the direction it had originally came from)in a faster speed than it was going before. While it flew off turbulently,as if was unsteady. When it flew off, I saw a single red blinking light in addition to the bright white light.((NUFORC Note: Date is approximate. Please see a similar case over Rhode Island on the evening of June 22, 2000. In the latter case, the object was seen on radar, following the aircraft. PD))