Investigations opened as horses across France found with ears cut off, eyes gouged out and genitals mutilated.

Horses have been found with ears cut off, eyes gouged out and genitals mutilated across France, prompting investigators to open more than 150 probes into a spate of killings and mutilations, agriculture Minister Julien Denormandie said on Wednesday.

“We have an unacceptable situation of absolutely sickening cruelty acts,” Denormandie told France Info radio.

“I hear the fear, the concerns, the disarray of horse owners,” he said, adding that a toll-free number was being made available to horse owners from Wednesday morning.

Police are yet to determine a motive; theories include a satanic rite, macabre trophy hunt or internet challenge.

A 50-year-old jobless man was arrested on Monday in eastern France as part of their investigations, but he was subsequently released without charge, a police source said on Tuesday.

The man had been detained on Monday after a computer-generated image of one of two people suspected of cutting horses in the Yonne department of central France was circulated.

“He denied the charges from the start and his alibi could be corroborated,” said Arnaud Laraize, a prosecutor in the central French city of Sens

French police at the weekend launched a search for two suspects in the Cote-d’Or region of eastern France after a stable owner told police of an intrusion on his premises during which one horse was wounded.

The Val-d’Oise department close to Paris recorded its first cases on Saturday: “Two mares were wounded, but survived.”