BOISE, Idaho (AP) — Four environmental groups have filed a lawsuit to prevent a federal agency from extending a wolf- and coyote-hunting derby onto additional public lands in east-central Idaho.

The lawsuit filed late Thursday in federal court in Idaho came less than two hours after the U.S. Bureau of Land Management approved Idaho for Wildlife's request for a permit. Defenders of Wildlife, the Center for Biological Diversity, Western Watersheds Project and Project Coyote say the BLM's actions are contrary to the federal government's wolf reintroduction efforts.

BLM officials say the impacts of an estimated 500 hunters on about 3 million acres of BLM land over a three-day period will not be significant. The event last winter was held on U.S. Forest Service land and private land. Hunters killed 21 coyotes but no wolves.