The incident happened when the children, aged between three-and-half and seven, went to wash their hands after their noon-meal in the premises of the school at Vettaikaraniruppu village, Nagapattinam District Collector T Munusamy said.
"All of a sudden, a swarm of poisonous wasps from a hive in a tree nearby attacked them," he said.
The children fainted after the wasps stung them.
The school management immediately rushed the students to a primary health centre where they were given treatment.