The proposed facility will include a shooting range, mock city and burn building, CNN has previously reported.On Tuesday, several police agencies entered the site as part of a joint operation to remove barricades that were blocking some of the entrances to the center, the Georgia Bureau of Investigation said.“Yesterday, several people threw rocks at police cars and attacked EMT’s outside the neighboring fire stations with rocks and bottles,” the bureau said Wednesday.“Task force members used various tactics to arrest individuals who were occupying makeshift treehouses.”The bureau said police cleared the area of makeshift treehouses and later found explosive devices, gasoline and road flares.For others, the facility poses environmental concerns at a time when the deadly impacts of climate change have become hard to ignore: The training center would carve out a chunk of forested land Atlanta leaders previously seemed to agree to preserve, though the city says officials are committed to replacing trees destroyed in construction."