Fourteen persons were killed and 25 injured, some seriously, when a car carrying Gelatine sticks and detonators blew up at Senthur village near Villupuram on Saturday, police said.
The injured were rushed to a government hospital in Tindivanam.
Initial reports had said 20 persons were killed. The car, carrying the explosives from a godown of a licensed dealer at Tirukoilur, developed engine problem as it entered the National Highway 47 at Senthur, police sources told PTI.
When one of the three occupants saw smoke and sparks emanating from the rear of the vehicle, he stopped the car.
As they were trying to douse the sparks with sand the car exploded, killing ten persons including the three occupants on the spot, while others succumbed to injuries on way to hospital.
Some of the victims were picking tamarind from a tree when the mishap occurred.
The impact of the explosion was so severe that nearby huts were gutted and even pucca buildings like a school in the vicinity damaged.
Police denied that the car was carrying RDX material. People used to pick ripe tamarind from the trees in the National Highways, to eke out a living during the summer, police said.
Police was inquiring whether the explosives were being transported illegally. The Villupuram district collector has ordered an inquiry into the mishap, the sources added.
Pattali Makkal Katchi founder S Ramadoss, who visited the spot, told media persons that the state government should pay relief of Rs five lakh to the next of kin of those killed and reconstruct the damaged houses.
Explosives and components used in bombs have been seized in recent weeks in Tamil Nadu and in the waters off the state's coast. Officials believe these materials were being smuggled to the LTTE in Sri Lanka.