The incident occurred when Khushbu Kumari (17), Putul Kumari (17) and Reshmi Kumari (18), had gone to take a bath in a pond at the village, Jandaha police station SHO Dhruv Narayan Prasad said.
Two of the girls jumped into the pond to save their friend from drowning, but in the event all three died, he added.
The bodies have been taken to Hajipur Sadar hospital for post-mortem.