BUENOS AIRES, Argentina -- Recent mutilations of cattle and horses in the Argentine countryside were the work of rodents, scientists said on Monday, not ritualistic slayings by extraterrestrials or vampires as some farmers feared.

Argentina's national food and animal health inspection service SENASA sent its own "X-files" scientists to the remote plains to look into the deaths of farm animals found mutilated and drained of blood. Frightened farmers claimed to have seen bright lights and UFOs in the area where the deaths occurred.

But SENASA officials said the dozens of livestock whose genitals, tongues and other organs appeared to have been removed with surgical precision were victims of rodents, foxes or other animals.

SENASA said the farm animals likely died from common infections and wild animals later mutilated the corpses.

"We see these as natural deaths (and) there is clear evidence of the presence of rodents and birds which led us to our conclusions," Reuters quoted SENASA President Bernardo Cane as telling reporters.

The strange circumstances surrounding the deaths -- one horse's hoof had a circle drawn into it and some animals were surrounded by charred grass -- led some locals to insist the deaths were the work of little green men, vampires or a satanic cult. SENASA gave no explanation for the burned grass and the circle on the hoof.

SENASA said its specialists conferred with scientists in Texas who had investigated similar cases in the 1970's and arrived at a similar conclusion.