All are from the same family hailing from Mawsawa village near Mawsynram (Sohra), they said.
The district officials said soon after consuming the wild mushroom collected from a nearby jungle, all members of the family were rushed to the hospital when they started vomiting.
Drisda Rapthap, her two children - a one year old and Iainehskhem Rapthap (7) and her brother in-law Ioki Dewkhaid (29) died, while her husband Synsharlang Dewkhaid, his mother and five other children were shifted to the Shillong Civil Hospital and Ganesh Das Hospital in critical condition, they said.
He said the magistrate has been asked to submit the report on the matter at the earliest.