Rome - Holidaymakers have been advised not to bathe along two stretches of the Italian coastline because of the invasion of Ostreopsis ovata - algae which, when they bloom, release neurotoxins into the air. People who come into direct contact with the algae can suffer respiratory problems or minor skin irritation.

Swimming has been banned at beaches near the northern city of Genoa after a 60-year-old man was taken to hospital on Friday.

Subsequent tests showed it was the same type of algae that caused 200 people in the Genoa area to seek hospital treatment last year.

The Italian health ministry said the algae do not represent a significant risk to health but insisted that the temporary bans had been put in place for the good of swimmers.

But the mayor of one resort has defied the ban at his local beach, accusing authorities of overreacting to the presence of the algae at Fregene, outside Rome.

Sporting an "I Love Fregene" T-shirt, Mario Canapini splashed about at the water's edge, applauded by business owners who say they are suffering financially because of the health warning being issued at the beginning of Italy's busiest holiday period.

"The water is clean. There is absolutely no danger," the mayor shouted to passing tourists, who nevertheless remained on dry land.

Mr Canapini, who risks a fine if he continues to go in the sea, said he felt his town was being penalised because other resorts along the same stretch of coastline still had open beaches.