Three children died and six were seriously unwell, after being given the diphtheria, tetanus and pertussis vaccine in Palamau, a district in Jharkhand.
The incident took place in Loinga village. According to villagers, the vaccines were given to children between the age of one and three years by nurses on Saturday.
The children started vomiting and had loose motion following the immunization process. They were admitted to the Sadar Hospital on Saturday evening. Three of them died on Sunday.
Chief Minister Raghubar Das ordered a probe into the incident. He also announced Rs 1 lakh compensation to the families of each of the dead.