Even as the police registered a case, a team of explosives experts will also probe into the cause of the massive explosion at Vetrivel Explosives Limited at T. Murungapatti near Thuraiyur.
Hours after the blast, the Deputy Controller of Explosives from Vellore arrived at the blast site to ascertain the details of the tragedy.
The Joint Chief of Explosives from Sivakasi landed at the blast site later to carry out investigation assisted by the police, a senior official said.
The unit was given licence by the Chief Controller of Explosives at Nagpur.
A senior official of Industrial Safety and Health said a thorough probe would be conducted into the blast and appropriate legal action would be initiated.
The building where the blast took place was manufacturing PETN explosives. Although only five workers were to be in the unit, a group of labourers had checked in to collect the materials, said another official.
Various theories were floated as to how the blast could have occurred.
A top police official told The Hindu that four teams had been constituted to pursue investigation into the blast. Uppilliyapuram police have registered a case under Section 304 (ii) ( culpable homicide not amounting to murder) of the IPC and under the provisions of the Explosive Substances Act.
The company had three PETN units, two detonating fuse units and three slurry units.
It had been exporting PETN explosives to Indonesia and supplying other substances to Neyveli Lignite Corporation, sources said.
The explosive substances were also being despatched for stone quarry and for digging wells, said an official.
