Colorado ? A black bear that attacked two campers last weekend remained free in Rocky Mountain National Park as officials closed more areas to visitors.

A trap has been set for the bear near Fern Lake, where two campers were bitten and clawed Sunday. Rangers were watching the trap day and night from a nearby cabin, park spokeswoman Kyle Patterson said.

She said rangers would kill the bear if they caught it because its aggressive behavior made it too dangerous to have in the park.

South of the park in Boulder, the city Open Space and Mountain Parks Department closed more trails around the National Center for Atmospheric Research because of several bear-human encounters.