The incident occurred at Kamarkhunti village yesterday, chief district medical officer (CDMO), Nuapada, Biranchi Narayan Panigrahy said.
"A medical team led by additional district medical officer (ADMO) Shantilata Das has rushed to the village today to treat the affected people", Panigrahy said.
The deceased, all teenaged girls, were identified as Bahini Majhi, Kapoor Majhi and Laxmi Majhi. They fell seriously ill after returning from the feast and never recovered.
Those who had fallen ill, were being treated in the village, the sources said, adding, enquiry into the incident was on.