The deceased, including members of one family and some friends, have been identified as Ajay A. More (16), Sonam Apte (15) and Madave More (45). They had taken supper Sunday night, besides a popular local sweet dish, modak, but they soon started vomiting, police said.
They were rushed to a nearby hospital but three of the victims succumbed after midnight.
Four others are still under observation, an official of Tasgaon police station said.
The incident occurred in Biranwadi area of Tasgaon, around 25 kms from Sangli district headquarters.
The official said that samples of rice, vegetables, and modak have been seized and sent for chemical analysis to Pune. Further investigations are on in the case.