Tourists in Barcelona's historic centre risk being egged by anarchist mobs who want to drive visitors out of the area.

Graffiti condemning tourism, describing it as a nightmare has also been sprawled across buildings in the Spanish city.

It comes after a tourist bus was recently attacked by masked anarchists, prompting initial fears that the activists were terrorists.

One tour operator has revealed how activists have been pelting his clients with eggs and is now treated as the 'enemy' by furious locals.

Anarchist groups in Spain have been targeting tourists who they blame for the rocketing price of accommodation in cities such as Barcelona as well as over-crowded streets

This demonstration in Barcelona, from 2014 is calling for an end to 'Binge Tourism'

Locals complain areas such as Barceloneta Beach are too overcrowded in the summer

Edgar Torras runs the Barcelona Segway Glides offering tours of the city centre. He said the relationship between locals in the city and those visiting has deteriorated dramatically in recent years.

He said the routes he can take around the city have been restricted due to overcrowding.

He told Bloomberg: 'Suddenly we seem to be the enemy.'

His business involves taking up to six people who pay €70 each for a three-hour tour through the Gothic Quarter, Ramblas and the old port. He runs two such tours a day during the summer months.

Recently he has been banned from going to Barceloneta beach by the city's authorities.

He said: 'This is the time we have to save.'

One message repeated across the city is: 'Never again a summer like this'. Locals in Barcelona blame tourists for overcrowding, taking space on the city's famous beach and even driving up the price of rental property.

It is claimed landlords can earn more money on short term lets through services like AirBnb

Last weekend, protesters erected banners with messages such as 'we do not want tourists in our buildings'.

Similar demonstrations have flared in other parts of Spain, the world's third tourism destination.

Other areas of Spain such as Palma de Mallorca have also seen anti-tourist incidents

Spanish prime minister Mariano Rajoy has been forced to defend the tourism industry, which represents 11 per cent of the country's economy

This summer in Palma de Majorca in the popular Balearic Islands, activists burst into the port, setting off flares of red smoke and throwing confetti over people eating at a restaurant.

Others assaulted a bus full of tourists in Barcelona, painting over its windscreen and giving passengers a fright.

Beyond these protests, officials too have started addressing the problem of overcrowding.

The Balearic Islands, for instance, have just limited to just over 623,000 the number of visitors that can stay in hotels or legal rental accommodation in one go.

Faced with the protests and criticism, Spanish Prime Minister Mariano Rajoy was forced to defend a sector that counts for 11 per cent of Spain's economic growth.

He said: 'I never thought I would have to defend the Spanish tourism sector, it's really unprecedented.'

Tourism is a major source of growth outside of Spain too.

According to the World Tourism Organization (UNWTO), one in 10 jobs worldwide is tied to a sector that generates 10 per cent of global GDP.

From 1995 to 2016, the number of international travellers went from 525 million to 1.2 billion thanks to low-cost companies and visitors from emerging markets like China, India and the Gulf countries.

As a result, some destinations are now sagging under the weight of tourists.

Dubrovnik in Croatia is a favourite with cruiseships - a popularity that soared even further when it was used as a backdrop in the smash TV series 'Game of Thrones'.

The walled old town is a delight of 17th- and 18th-century architecture. Locals, though, do their best to avoid it, saying it is almost impossible to move in the congestion.

In Florence, meanwhile, authorities have started hosing down public spots such as church steps where many visitors congregate to eat picnics, to stop them from sitting down.