Pig Heads
Heads of pigs are placed on the ground of the entrance of a warehouse of Belgian supermarket group Delhaize in Zellik, near Brussels, August 12, 2011. Image Credit: Reuters

An investigation is underway after pig heads were discovered at an Islamic school and a Catholic church in western Sydney last weekend.

Police have condemned the unknown perpetrators for ''random acts of stupidity and desecration" after the heads were found at the two sites, which are around five kilometres apart.

Fairfield Superintendent Peter Lennon told the Sydney Morning Herald that the incidents took place on the evening of 28 April. The miscreants reportedly threw a head at the front gate of the school in Cecil Park, while another head was deposited on a spike outside the church.

The head at the church was discovered by building workers preparing for its reopening, while the one at the school was found by cleaners and teachers.

Lennon described the crime as "un-Australian" and said his team has been unable to establish a motive so far.

"We haven't seen anything like this before ... it's un-Australian, it's just senseless and we urge any witnesses to come forward," he said.

Police are examining CCTV cameras from nearby locations to catch those responsible and has also asked members of the public to come forward and report any information they may have in connection to the matter.

Earlier this year, a 21-year-old man was arrested for dumping a pig's head outside a mosque in Berkshire.

Rory Rowbottom, of Poffley Place in Thatcham, dumped the animal's head at the mosque on Pound Street in Newbury on 23 October last year.

Rowbottom was charged on a count of racially aggravated harassment and a section 4 public order offence, for which he pleaded guilty.

At the time of Rowbottom's arrest, Lucky Nizami, of the Newbury Mosque Committee, told the BBC: "The Muslim community is very tolerant of others' beliefs, but hold several things very close to them; those are the Koran, the Prophet and the mosque.

"It was therefore beyond the understanding of the community why anyone would wish to insult them by directly attacking one of those, in this case the mosque."

Eating pork is forbidden in Islam and pigs are considered unclean and impure animals.

"We do not doubt for an instant that the pig is a dirty and filthy animal, and that eating it is harmful to man. Moreover it lives on dirt and filth, and it is something that is off-putting to those of a sound nature who refuse to touch it, because eating it is either a cause or a sign of a person's oddness," says a prominent website which offers guidance on the subject.