The fine was leveled by left-wing Barcelona mayor Ada Colau in a crackdown on unregulated tourism in the city where home rental sites have allegedly marketed apartments without listing them on the Catalan Tourism Register.

The capital of Spain’s northeastern Catalonia region, Barcelona is famed for its Belle Epoque architecture, museums, and night life.

It is not the first time the city has fined San Francisco-based Airbnb, one of the fastest-growing start-ups of the so-called ‘sharing economy’ valued at around $25 billion.

The Barcelona council reported that Airbnb and Homeaway were repeat offenders having illegally advertised 3,812 and 1,744 properties respectively. An additional nine rental sites are expected to also face fines up to 30,000 euros for failing to follow regional tourism laws.

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“It shouldn’t be possible that thousands of apartments are operating without a license, illegally, without paying tax and at the peril of neighboring residents,” Colau said on a Catalonian radio channel on Thursday.

Cities like Berlin, Paris, and Barcelona say home-sharing websites for tourists deprive locals of apartments for permanent rent and push up prices for homes remaining on the market. Barcelona has seen a surge in tourism and attracts around 27 million visitors a year.

Airbnb said it was saddened by the decision and would appeal.

“Less than a month ago we met with officials and Airbnb committed to work together in the best interests of the city. Airbnb is part of the solution in Barcelona,” the Catalan division of Airbnb said in a statement on Thursday.