The peace and tranquillity of the countryside has been shattered by a series of gruesome attacks on livestock in three Swiss cantons.
Farmers are calling on the public for help in tracking down whoever is responsible for 30 incidents of animal mutilation over the past few weeks.
In the most recent case reported by police, a bull belonging to a farmer in canton Solothurn bled to death after its genitals were slashed in a knife attack.
The authorities believe the sexually motivated attacks – on cows, sheep, horses, cats and rabbits – are likely to have been carried out by the same person.
Mark Rissi, spokesman for Swiss Animal Protection (SAP), told swissinfo he could not recall a similar series of incidents in Switzerland.
"I have never heard of a serial attacker of this kind. I think it must be the first time that we’ve seen such attacks on this scale," he said.
Rissi added that horses and cats were usually the victims of this kind of abuse.
Police are baffled by the spate of attacks and are urgently appealing for any information which could lead to an arrest. They have warned farmers and members of the public to be on their guard and to remain vigilant.
Farmer Urs Kamber from canton Solothurn told Swiss television earlier this week how he woke to discover one of his lambs had been beheaded.
"On the morning in question I heard the lambs making frantic noises. When I called them they came running immediately.
"I noticed that one small lamb was missing, so I went to check. It was a huge shock to discover this 14-day-old animal lying on the ground with its head cut off."
Over the past two months the unknown attacker has also mutilated animals in cantons Basel Country and Aargau.
Farmers across the region have started keeping a close eye on herds and have discussed organising night-time patrols.
"Farmers are looking more closely at people walking near their pastures and at unknown cars using country lanes. That’s all we can do at the moment," said farmers’ union official Stefan Weber.
Investigators have enlisted the help of Basel-based psychiatrist Marc Graf in an attempt to close the net around the attacker.
In an interview with the Basler Zeitung, Graf said it was difficult to establish an accurate criminal profile. But he believes the person police are looking for is male and likely to be between 20 and 40 years old.
"It could be someone who is marginalised in society or it could equally well be an individual who is well integrated," he said.
Experts generally agree that violent acts of this kind are nearly always the work of individuals and they say it is difficult for those who plan and carry them out to recruit accomplices.
According to Graf, one scenario which should not be excluded from police enquiries is that the attacker is simply "experimenting" with animals and that his real intention is to act out his fantasies – sexual or otherwise – on humans.
As the police investigation continues, SAP has offered a reward of around SFr20,000 ($15,400) for information which leads to an arrest.
"We have received calls urging us to increase the amount of reward money," said Rissi. He added that people had expressed a willingness to make a contribution towards the reward fund.
Both SAP and the regional section of the Swiss Farmers’ Union are warning people not to take the law into their own hands should they come across the attacker.
Meanwhile a Swiss-based foundation for the legal rights of animals has called on the authorities to investigate such incidents in the same way as they would if the victims were humans.
The Foundation for the Animal in the Law argues that investigators often make only half-hearted attempts to track down the perpetrators of violence against animals.
It is appealing for more political will and investment in the investigation and prosecution of anyone accused of animal mutilation.
Police in three Swiss cantons have reported a spate of around 30 attacks on livestock over the past two months.
The attacks have taken place in cantons Basel Country, Aargau and Solothurn.
The police are working on the assumption that the same individual is responsible for all the attacks.
A reward of around SFr20,000 is being offered for any evidence which leads to a successful arrest.