RENO, Nev. (AP) - Wild-horse advocates are calling for an independent investigation after the deaths of nine mustangs so far in a government roundup of the animals on the range north of Reno.

San Rafael, Calif.-based In Defense of Animals and Colorado Springs, Colo.-based Cloud Foundation criticized the U.S. Bureau of Land Management's handling of the roundup after two more deaths this past week.

A contractor is using two helicopters under BLM supervision to drive horses in the Calico Mountain Complex to corrals. The horses are then being trucked to a Fallon facility.

Horse activists maintain a colt was run so hard and long during the roundup that the hoof walls of its two hind feet came off. The colt was euthanized Thursday.

BLM officials disputed the groups' accounts of the latest deaths.