All 80 members of the European Spirit of Youth Orchestra were rushed to the Santa Chiara Emergency Room in Trento, Italy, suffering from dehydration after an outbreak of vomiting and diarrhoea.
About twenty young musicians received prolonged treatment and two were detained in hospital overnight.
The problem was traced to a picturesque fountain in the small town of Belluno, where the orchestra had stopped for a drink of water. Officials say this was due to current repairs to the aqueduct.
The orchestra aims to continue its tour with conductor Igor Coretti-Kuret.