Some 20,000 protesters hit the streets of Palma in Mallorca Sunday for a mass demonstration against overtourism, demanding changes to a touristic model they say is harming the Spanish Mediterranean island.

Under the slogan "Let's change course and set limits on tourism", the demonstrators formed a sea of brightly-coloured flags and banners as they surged through the city's most visited streets, in the latest in a wave of mass anti-tourism protests in Spain.

"Your luxury, our misery," read one sign, while another placard said: "This isn't tourismophobia, it's numbers: 1,232,014 residents, 18 million tourists."

The protests were called by some 80 organisations and social groups who want limits to be placed on excessive tourism in the Balearic Isles, whose main three islands are Mallorca, Menorca and Ibiza.

They say the current model of tourism has stretched public services to breaking point, harms natural resources and makes local access to housing increasingly difficult.

Organisers claimed that 50,000 joined the protests, with police estimating 20,000 participants. Earlier, the central government's delegation in the islands had said 12,000.

Last year, a record 17.8 million people visited the Balearic Islands, from mainland Spain and abroad, and the figures are expected to be even higher this year.

The demonstration followed another mass protest across the archipelago's three main islands at the end of May, in which many thousands of marchers hit the streets to demand steps to limit overtourism under the slogan: "Our islands are not for sale".

"From a practical point of view, it is a legitimate economic activity. But as an economic activity, it should ultimately be regulated in the same way as hotels," said architect and urban planning expert Jose Maria Ezquiaga, who told TVE public television he believes tourist rental flats should require the approval of local residents' associations.

"It should be local property owners who set the rules of the game and decide whether or not certain formats are acceptable," he said.

And Manuel de la Calle, an expert in the field of tourism and business, said imposing a tourist tax could be part of the solution.

"It is one of the possible solutions that could be put in place. It will not reduce the flow of tourism, but it will generate resources that can be driven into tourism management or other avenues to help the local population," he told TVE.