Twenty-one school students were hospitalised after being attacked by a swarm of bees during a trek in Junnar tehsil of Pune district on Sunday, an official said.

A group of 64 students of Classes VIII and IX of Khed-based Dynamic English Medium School along with four teachers and as many non-teaching staff were trekking near Amba Ambika caves when the incident took place at 4 pm, he said.