BOZEMAN, Mont. (AP) — Yellowstone National Park plans to increase security after fences were damaged at a bison capturing facility outside the park, in one case undoing efforts to certify the bison hadn't been exposed to a wildlife disease and could be transferred to an Indian reservation.

The bison are captured as they leave the park in the winter to reduce the size of the herd and to prevent the spread of brucellosis.

Fifty-two bison escaped through two layers of damaged fence at the Stephens Creek Capture Facility near Gardiner in January. Officials have said the bulls were about 6 months from being certified as brucellosis free.

Late Wednesday or early Thursday, at least 350 bison were inside the damaged fencing. Most were re-captured.

Park Superintendent Dan Wenk on Friday declined to say what extra security measures were planned.