The students were shifted to a Sub-district Hospital in Basohli. Later, three of them were shifted to a district hospital here for further treatment, a school official said.
The students in Basholi belt of the district started "vomiting and showed diarrhoea-like symptoms", he said.
The school administration has, however, denied adulterated food as the likely cause of the illness.
A direction has been issued to the officials to collect the food sample, and the school authorities have been told to take proper care of the remaining students, Tehsildar Samrinder Singh said.
Worried parents rushed to the hospital to see the children, he added.