Priti Kumari (16), Babu Kumary (19), daughters of Arun Kumar Rai, and Kavita Kumari (20), daughter of Rai's brother Vidyanand Rai, went to a marketplace near Bairanpur village under Viraul police station area last evening where they consumed a poisonous substance.
While Priti and Kavita died on way to a local primary health centre, Babu passed away around midnight during treatment, Deputy Superintendent of Police (DSP) Anjani Kumar Singh said.
The bodies have been sent to Darbhanga Medical College-cum-Hospital (DHCH).