"They are everywhere, " said Shoba Raba, director of policy at the Indian branch of Basic Needs, an international mental health and development charity.
Raba said that faith healers tend to be well versed in Ayurveda, a field of indigenous medicine that focuses on lifestyle habits such as diet and fitness.
An alert has been declared for the Marcal and Torna rivers, and Mr Illes said workers were "desperately" trying to stop contamination of the Raba and Danube rivers.