ALBUQUERQUE, N.M. » A federal judge says a lawsuit by environmental groups to keep the government from aggressively removing endangered Mexican gray wolves that have attacked livestock can move forward.

U.S. District Judge David Bury this week rejected a motion by the U.S. Fish and Wildlife Service to throw out the case filed nearly a year ago by several conservation organizations.

The government began reintroducing Mexican wolves to the Southwest in 1998 in a 4 million acre territory along the Arizona-New Mexico line. A survey last year found 52 wolves scattered between the two states.

The plaintiffs are challenging a "three strikes" rule that calls for wolves to be removed from the wild or killed if they prey on livestock more than twice a year.