Employees at the Museum of Contemporary Art in Basel, Switzerland couldn’t go to work on Thursday morning after unknown perpetrators barricaded the front door with a hastily-constructed brick wall, BZ Basel reports.

Interestingly, the museum has declined to press charges or even file a police complaint. According to the museum’s spokesperson Michael Mathis the museum views the clandestine episode as “artwork.”

The brick-and-wood barrier was quickly removed and the incident did not greatly affect the staff’s workday. (See Art Basel Announces Artist Lineup for Unlimited and Art Basel Plans Rirkrit Tiravanija Art Installation).

Mathis speculated that the “artwork” was probably constructed by a collective of artists and squatters called Atopie. The group recently organized a two-week series of exhibitions and talks in an abandoned property in central Basel, which was forcibly shut down and evacuated by the police.

On Thursday evening the group uploaded images to its Facebook page confirming that they did indeed build the wall. The photos show brick walls propped up in front of the entrances of the Basel Museum of Contemporary Art, The Basel Architecture Museum, and the abandoned house from which the group was evicted.

Atopie did not respond to a request for comment but, according to their website, the group wishes to “claim space for society, culture, and alternative lifestyles,” and “demands space to live and exist in without consumerism and commercialism.”