A two-year-old child was killed and six people injured after a grenade exploded inside the home of Jasbir Singh, a local BJP leader, in Jammu and Kashmir's Rajouri yesterday evening.
It is unclear, at this time, if the incident was a terrorist attack.
Officials have said the explosion initially wounded seven family members, including Mr Singh.
A two-year-old nephew of Mr Singh - identified by news agency PTI as Veer - later died from injuries sustained in the blast while receiving treatment at a government hospital.
Sources told PTI that the child's body has handed over to the family for the last rites.
The BJP has strongly condemned the attack and Ravinder Rana, the head of the party's J&K unit, has appealed to the police to immediately arrest those responsible.
Mr Singh's family has alleged inadequate security cover, according to PTI.
The family told police a grenade had been thrown at their house. Initial reports suggest it exploded on the rooftop.
Police rushed to the home and collected samples to ascertain the nature of the explosion.
Soon afterwards locals gathered and raised slogans against the administration.
A shutdown call was sounded after the explosion and shops in most parts of the town are closed.
On Monday another local BJP leader - Ghulam Rasool Dar, a village sarpanch and the district head of the BJP's Kisan Morcha - and his wife were shot dead in south Kashmir's Anantnag town.
With input from PTI