Police said they were investigating the reason behind the incident, which took place in Jorhat district.
Superintendent of Police Amanjeet Kaur said a case of unnatural death had been registered. She said the victim, Bonti Chutia, died of burn injuries, while her husband, Someswar Chutia, had also sustained 35 percent burn injuries.
Kaur clarified that the victim was not the who was shown on television kissing Congress vice president Rahul Gandhi.
"We have talked to people and came to know that although she (the victim) came to the venue Wednesday to interact with the Congress leader, she stayed outside the programme for some reasons," Kaur said.
"We also came to know from the neighbours that both the husband and wife had a strained relationship for a long time and that could be one of the reasons for the incident," she said.