Things are heating up in the run up to the third edition of Art Lima, Peru’s top contemporary art fair, and not in a good way.

A number of participants in the fair—slated to take place on April 23-26—have pulled out to protest against a series of actions carried out by the mayor of Lima, Luis Castañeda Lossio, which they consider are attacking freedom of expression.

The problems began when Castañeda Lossio ordered the cover-up of several street art murals across the city, including one depicting the indigenous revolutionary Túpac Katari, which caused outrage in Lima’s artistic community, PBS reported.

So when the art fair made public a sponsorship agreement with the Municipality of Lima, led by Castañeda Lossio, on March 17, several participants pulled out from the fair immediately. Among them are Andrea Ferrero, a dealer from the Peruvian gallery Revolver, the bookshop Inestable, and artists Eduardo Tokeshi, Claudia Coca, Ramiro Llona, and Alfredo Márquez, Correo reports.

On March 19, Art Lima announced on its Facebook page that it would drop the agreement with Castañeda Lossio. But it might be too late for many. “The damage is done,” Ferrero told the Art Newspaper.