Eight students, who fell ill apparently after inhaling toxic gas emitted by a nearby sugar mill on October 10, were shifted to Meerut's hospital from Shamli district.
Chief Medical Officer (CMO) of Shamli hospital Raj Kumar said the eight girls were shifted to Meerut's medical college for treatment.
Meanwhile, the school remained close for the fouth consecutive day.
An official statement had said some 50 to 60 children were rushed to nearby hospitals for first aid but according to unofficial figures, around 300 had complained of breathing problems, nausea and a burning sensation in their eyes.
Their condition, however, improved gradually, the CMO said, adding that most of them were discharged.
Uttar Pradesh Chief Minister Yogi Adityanath had ordered a probe into the matter by the commissioner of the Saharanpur division under which Shamli falls.