The students, according to the reports, had huddled together for a group online study owing to poor internet connectivity at Mundagam village.
When the students did not return home by evening, their parents went looking for them and found the three lying in an unconscious state on the hilltop, the police said.
The students were taken to a nearby hospital in Brahmanpada. Sub Divisional Police Officer, G Udayagiri, Tirupati Rao Patnaik, has said that one of the students was in a critical state when he was taken to the hospital. The other two were said to be stable.
All three have been shifted to the district headquarters hospital at Phulbani, Patnaik said.
The students were identified as Dhiren Digal (17), Pinku Mallick (17) and Panchanan Behera (18). Chief District Medical Officer, Kandhamal, Dr. Monoj Upadhay said their condition was now stable.
"Students usually go to Digi hilltop where they can easily access mobile internet," a villager said.
(With agency inputs)
