An unknown graffiti artist struck Saturday in Sofia, turning a monument to Soviet soldiers into a pantheon of superheroes and pop culture icons, including Superman, Captain America, Robin, the Joker, Santa Claus, and Ronald McDonald. The Soviet flag was painted over as America's star-spangled banner and the phrase "in step with the times" was spray-painted below in Bulgarian. Although the eye-catching street art was an immediate hit with the public, the paint job has now been cleaned off.

Both Bulgarian and Russian authorities found the graffiti art offensive, with Bulgarian culture minister Vezhdi Rashidov maintaining that Bulgaria's socialist history should not be erased by vandalism, according to The Sofia Echo. The Russian embassy, meanwhile, called the act "outrageous" and noted its "exceptional cynicism," AFP reports. A group of non-profits including Forum Russia-Bulgaria paid to have the monument cleaned, and workers accomplished the task Tuesday morning, laboring in the wee hours to avoid clashes with fans of the graffiti. The unknown artist — who has been dubbed the "Banksy of Bulgaria" — faces charges of vandalism if caught.

According to Balkan Insight, a Facebook group with almost 2,000 members was formed in support of the work of street art, whose page erupted with angry posts when the sculpture was cleaned. The monument, which represents the Red Army's advance on Nazi-allied Bulgaria in 1944, has been a frequent target of graffiti in the past.