Eight others were reportedly injured in the incident, which occurred on Tuesday evening and are in a serious condition.
Stalin announced a relief of Rs one lakh to the injured persons admitted in the Kallakurichi government hospital.
The deceased victims include Khaleed (23), Shah Alam (25), Shaikh Basheer (67) and Ayyasamy (62). The police said it is yet to identify the fifth deceased victim.
Police sources told IANS that the mishap occurred due to a short circuit in an electric line and further investigation is on to ascertain the exact cause. A grocery shop was allegedly converted into a firecracker shop ahead of Diwali and was doing brisk business when the incident occurred.
The whole building was engulfed in fire and the police and fire personnel from Sankarapuram and Kallakurichi arrived at the spot to douse the fire.
Kallakurichi District Collector, P.N. Sridhar told media that the fire was doused after nearly three hours of intense efforts by the team of fire personnel and the police units that rushed to the spot.
The team cordoned off the area and started rescue operations as well as saved the grievously injured from the fire engulfed building.
State Minister, E.V. Velu reached the spot and visited the injured persons at the Kallakurichi government hospital on the same day of the incident.
The police said further investigation is on and whether the grocery shop that was converted into a firecracker shop had the mandatory license to conduct business. Whether the shop had the precautionary measures required to conduct a firecracker business, the police added.
The state government had issued warnings to the people and the firecracker manufacturers and traders to be safe during the Diwali season.