Story highlights Police in the town of Grenchen uncovered the pigs Friday

"We can't say yet it is a hate crime in those words," police chief says

An unsigned flier said the act was a "protest against the growing expansion of Islam in Switzerland"

"It is an escalation" in Switzerland, "where Christians and Muslims have all been living together," imam says

Muslims in Switzerland are responding with shock and outrage after a pig carcass and severed swine heads were discovered buried at the site of a proposed mosque.

Police in the town of Grenchen uncovered the pigs Friday after they received an anonymous message claiming that someone had buried the body parts and spilled 120 liters of blood from the animals in an effort to desecrate the ground to halt the construction of the mosque.

Pork and pork byproducts are haram, or forbidden, in Islam.

The unsigned flier, written in German, says "This operation was done (conducted) to protest against the growing expansion of Islam in Switzerland," and says that a similar desecration in Spain earlier halted another mosque construction project.

Thomas Suber, chief of the Solothurn Canton police, told CNN by phone that there were no suspects currently, but that a full investigation is under way.

"We can't say yet it is a hate crime in those words, but it could have been done to stop the mosque," said Suber.

Suber said that whoever is responsible may be brought up on environmental pollution charges.

The police chief says that veterinary health officials have been called in to find if pig's blood has in fact been spilled, and that charges may be filed over illegal dumping of animal parts in addition to other potential criminal charges.

But for Muslims in Switzerland, it's just the latest sign that they are being victimized by some in the far right.

Abdel Azziz Qaasim Illi, spokesman for Switzerland's Central Islamic Council said the deed "crossed a line" that had already been pushed against Muslims since a popular referendum in 2009 banned the construction of new minarets.

"Since the ban on minarets there's been an increase in Islamophobia and Islamophobic events, so it was not really surprising" said Illi. "But it is an escalation in Switzerland because this is a peaceful country where Christians and Muslims have all been living together... and we are a bit afraid this may increase."

There are an estimated 500,000 Muslims in Switzerland, out of a population of more than 7 million says Illi, who admitted that the population is rising but that most Swiss Muslims were immigrants from Albania and elsewhere in the Balkans, where there is a tradition of moderate Islam.

The property had been purchased by the local Muslim community several years ago from a Swiss far right political activist. The man claimed that he had not been informed that it would be used for a mosque and had fought the sale in court, before ultimately losing his civil case recently allowing construction to go forward.

"We can just wait for the next rain or snowfall to cleanse the ground, so we do not fear from this side anything," said Illi.

"But on the other hand it's an emotional thing, it means that there are actually people in this society who deny the right of Muslims when it comes to a mosque in Switzerland and this is something that hurts us."