New Jersey state biologists euthanized four black bears in recent weeks in Ramapo Mountain State Forest. Officials said the bears had been acting aggressively.
The forest is barricaded off to the public and the state police have been keeping hikers from climbing up the mountain.
Authorities say that there have been aggressive bears reported there by residents and hikers.
In fact, in a nearby park, 8 hikers said they have been pursued by a black bear.
According to the New Jersey Department of Environmental Protection, the bears had shown no signs of being fearful of people.
Officials believe illegal feeding of the bears could be to blame.
Elaine Dunn, an advocate for Bear Education And Resource (BEAR), a program that educates people about black bears, said bears are usually "timid and nonaggressive."