Anti-mass migration protesters have built a wall at the entrance to the Austrian Green Party headquarters to protest the party’s stance on mass migration.

Members of the Green party of Austria had a shock when they arrived Monday morning to their headquarters in the Austrian capital of Vienna. The entrance to the building was made inaccessible by a concrete brick wall that had been erected overnight, and Austrian media has alleged that the hipster-right Identitarian youth movement are responsible for the act.

However, the Identitarians have not claimed responsibility, but said that the wall was likely built in order to protest the Green party, who they say endanger Europeans via their open borders ideology, Austria’s Kronen Zeitung reports.

Sympathisers of the Austrian branch of the anti-mass migration Identitarian movement are said to have bricked up the entrance to the building in the early hours of Monday morning using aerated concrete bricks. The wall, which measured just over five feet in height, was also spray painted with the words “Pro border” and “Your Fault!” with a Christian cross, a reference to the beheading of a priest in Normandy by Islamic State extremists only a week before.

The Green Party have issued a statement to the Austrian press saying that they were able to tear the wall down at around 8:30 am, not long after the first workers arrived at the office. They also said that they would be looking into pressing charges for damages seeking financial retribution against whoever was involved in the protest.

The Austrian media has claimed that the Identitarians are behind the incident, the group have themselves not taken responsibility. While the protest bares striking similarity to an Identitarian affiliated group in the German city of Halle called Kontra Kultur, they claim they received the news and pictures of the protest via an anonymous email.

Breitbart London was able to acquire the anonymous email, which was sent from a ‘Tor’ email address. Tor, or The Onion Router, is a heavily encrypted service that allows its users to be totally anonymous online. The email claims that the action was done because the Austrian Green Party, in their words, are complicit regarding the recent terror attacks in France and Germany.

They claim that the party, via its promotion of open borders and rallying against deportation of migrants, has contributed to the creation of a climate where criticism of mass migration is labelled as xenophobic racism.

According to the letter the wall symbolises the Green’s “blocked and bricked up” mentality when it comes to dissenting opinions and their promotion of hate speech laws, which in places like Germany have led to raids of people’s homes and arrests for merely being critical of migrants on social media.

The letter ends with a warning to the Greens reading: “You are destroying the future of our generation. Your two-faced politics has created us and we will do away with you!”