AUSTIN, Texas — Employees at several Austin businesses have found stickers saying “exclusively for white people” placed on their windows, sparking an investigation into their origin and condemnation from the mayor.

Mayor Steve Adler said the stickers discovered Wednesday morning were “an appalling and offensive display of ignorance in our city.”

The stickers also say “Maximum of 5 colored customers / colored BOH staff accepted,” apparently referring to the “back of house” operations at a restaurant. They featured a city of Austin logo and claimed to be “sponsored by the City of Austin Contemporary Partition and Restoration Program,” though no such program exists. The city has said the use of its logo was unauthorized.

Austin is one of the fastest-growing cities in the U.S. and is confronting increasing questions about economic and racial segregation as real estate prices skyrocket around its urban core.

Several business owners and employees said the stickers unnerved them.

April Jensen, who works at the Sugar Mama’s Bakeshop, told the newspaper “it kind of hurt” when she read the sticker. “I don’t really understand the message behind it,” said Jensen, who is African-American. “All types of customers come in here.”

Bryce Bencivengo, spokesman for the city of Austin, told the San Antonio Express-News that city officials along with the Austin police are investigating the stickers’ origin.