A woman holds her son who was injured in the blast. (PTI)

Chennai, April 8: Slurry is supposed to be safer than gelatin sticks. Not any more, it seems, after yesterday’s blast.

Investigators probing the jeep explosion that killed over a dozen and damaged homes a kilometre away in a village near Chennai also came upon 375 metres of fuse wire and 150 electric detonators, though they are supposed to be transported separately under the Central Explosives Rules.

But more than violation of safety norms, the sleuths are baffled by the impact of the blast even as the government today confirmed that the jeep was carrying 200 kg of slurry, a supposedly “safer mix”.

Sources said after the Centre banned sale, use and transport of Nitroglycerine-based explosives in December 2004, as their longer shelf life was being misused by extremists, slurry had “almost substituted” gelatin sticks in civilian projects, though its efficacy was only 50-60 per cent.

Moreover, the jeep carrying the slurry for a contractor working for the National Highways Authority of India was a licensed vehicle transporting the stuff from a licensed dealer.

Police sources suspect the blast at Sendur in Villupuram district could have been triggered by the over-heating of the combustible substance the vehicle was carrying. But nobody here in the administration has a clue to whether the Centre’s revised guidelines for handling or transporting explosives had been effectively conveyed and whether periodic inspections were done to avert “unauthorised mix” of the substances involved.

The sources said all these questions would have to be delved into when authorities review safety measures in the wake of yesterday’s blast, the first of its kind in recent years in Tamil Nadu, where explosions have mainly occurred in fireworks units.

The suggestions of the Nagpur-based Petroleum and Explosives Safety Organisation, which monitors manufacture and use of all licensed explosives in the country, could also come up, the sources added.

The official toll remained 16 till late this evening. The sources said five of the critically wounded were in serious condition.

Navnit said the blast had flattened about 30 buildings, but if those that had suffered minor damages were taken into account, the number could cross 100.

“The mishap has raised grave doubts in the backdrop of an increase in smuggling of explosives across the Palk Strait to Tamil militants in Sri Lanka and gun-running,” said Opposition leader Jayalalithaa, who visited the victims late last evening.

The police today arrested two persons in connection with the blast. One of them is Nagappan, an employee of Sri Sakthi Explosives, from whose godown the deadly stuff was loaded into the jeep yesterday, and Annamalai, the company’s manager. Its owner, Manalipatti Sekar, was said to be detained last night, but police sources said they were still looking for Sekar.