The world's biggest outbreak of Legionnaire's disease hit the city or Murcia in south-east Spain. It has killed three people, affected more than 300, and last week there were 480 suspected cases.
Buildings which have been found to have the bacterium responsible for Legionnaire's disease include the regional health service HQ.
The bacterium is found in water pipes and air conditioning units.
Authorities says that the outbreak is no longer in its infectious stage.