Three fifth-grade students of a school in the Mekong Delta province of Hau Giang were still unconscious as of Saturday morning after being admitted to the local hospital with suspected pesticide poisoning on Friday.
One student, Tran Quoc Trung, regained consciousness on Friday while the other three - Truong Quoc Thang, Vo Minh Kha, and Lam Anh Minh - were yet to regain consciousness, doctors at Can Tho City's Children Hospital said.
However, none of them were in critical condition, they added.
Nguyen Ba Tuoc, principal of the Long Thanh 1 Primary School, said the four students lost consciousness and their bodies turned pale around five minutes after coming back to class after a break.
Some of their classmates said they saw Trung, Thang, Kha and Minh drinking from a bottle of milky water during the break, but did not know what the drink was.
Police in Hau Giang's Phung Hiep District are investigating the incident.