Pizzeria Alcamo in Jönköping – which is apparently in southern Sweden – was closed Thursday and by today, 593 people said they were sick after a visit or a slice.

It is not yet known whether patrons fell ill as a result of food poisoning or a fast-spreading outbreak of the winter vomiting virus.

The council's health and safety office has carried out tests on kebab meat, iceberg lettuce and kebab sauce in a bid to isolate the source of the outbreak.