Despite the government making efforts to control the use of ammonium nitrate, which is commonly available as fertiliser, it continues to be the most favourite explosive material used in almost all the blasts during last three years.

Coverage: Delhi Serial Blasts

The government had planned a strong controlling regime to check misuse of ammonium nitrate, key component for manufacturing deadly RDX explosive, but the proposal seems yet to see the light of day.

The terror attacks in Uttar Pradesh [Images] courts in November 2007 and subsequent bombings in Jaipur [Images], Bangalore, Ahmadabad and Delhi [Images] point towards the metamorphosis of the chemical from innocuous fertiliser into a terror toy.

Ammonium nitrate is not a high-quality explosive like RDX but intelligent use of shrapnel, packing and proper fuel mix like diesel converts it into a low-cost-high-impact explosive.

"Ammonium nitrate produces oxygen at a very fast rate thereby creating an explosion. The basic difference between the RDX and ammonium nitrate is that the former can be used alone for causing blasts whereas the latter is to be laced with some fuel for causing the explosion," Head of Explosives Unit, Central Institute of Mining and Fuel Research, Dhanbad, R R Singh said.

A timer device, which could be a simple microchip, is embedded in the entire package and can be programmed like a digital clock. It creates spark at scheduled time and detonates the package.

There has been some amount of laxity to check the movement of the chemical, says a Home Ministry official, adding, "We require a strong controlling regime to monitor its misuse and ensure that its offenders were booked under the Indian Explosive Act".

Investigations into Bangalore and Ahmadabad blasts have given light to the fact that innocuous-looking material are being used for lethal purposes.

Bombs of about five kilograms laced with dangerous mix of diesel, gelatin, nails, nut-bolts, ball bearings and pebbles were used during the attacks. None of these materials are banned from trading in the country and can be easily procured from local markets.

"These bombs can be easily manufactured by locally available material. There is no need of courier and hence the chances of getting caught are also low. Most importantly, these explosions do not require high-end detonators as required with RDX," a UP Police official said.

"The concentration of ammonium nitrate while mixing with diesel is very important in the bomb-making process," he said.
 
The explosive needs to be packed at optimum tightness and fitted with accurately positioned shrapnel to cause maximum damage, he said.

The Home Ministry cited frequent of use of the compound in a number of recent blasts and officials felt that it was primarily the responsibility of transport, police and revenue authorities of the state governments to ensure that it did not fall in wrong hands.

However, there was laxity on part of these wings as ammonium nitrate continued to be smuggled out especially from quarries in Andhra Pradesh and that there was no stock check done by the state authorities, they said.