At least 13 people were killed and several others injured in a blast in a moving car outside the Red Fort Metro Station in Delhi on November 10. While details of what caused the blast remain sketchy, it could have been triggered by an improvised explosive device (IED). A former Director General of the National Security Guard explains how IEDs work and why there is a need for a holistic national counter-IED policy.***An improvised explosive device (IED), in many ways, is an embodiment of the collective darkness of the human psyche encased in a mid-sized container; it can maim, kill and traumatise complete strangers with impunity.Go-to for terroristsIEDs are the preferred weapons of choice for terrorists of multiple hues. This is primarily due to two factors. First, IED attacks entail almost no personal risk to the perpetrator (except in suicide blasts), while maximising casualties and mayhem; second, IEDs can be easily fabricated by terrorists from material which are not too difficult to procure.A typical IED has five components: a container, a power-source (battery), an initiator (detonator), a switch and finally, explosives. Triggering the switch through various methods initiates the circuit, culminating in the blast. In addition, IEDs also have enhancements such as ball bearings, nails, metal parts and potentially even hazardous chemicals to make the impact more sinister.Most IED components and enhancements except the detonator, can be improvised out of material often available off-the-shelf. Most terrorists, world over, prefer commercially produced detonators, although Ibrahim-al-Asiri, the chief bomb maker of Al-Qaeda, is believed to have mastered fabricating home-made detonators. Still, such detonators are considered unstable and dangerous to handle due to a variety of factors.Story continues below this adCarry ‘signature’ of group involvedIt is important to know the source and availability of IED components, both to understand how terrorists access such material (more on that later), as well as to facilitate conduct of post-blast analysis of an IED event in the country by investigating agencies.The nature of explosives — whether they are (1) military grade (TNT, RDX, etc.), (2) commercial (dynamite, slurry explosives, etc.), (3) homemade (by extracting explosive material from common precursor chemicals/materials and ‘cooking’ a mix; for instance, Ammonium Nitrate Fuel Oil or ANFO) — provide valuable clues to the investigator regarding the possible terror groups involved. It needs to be noted that terror groups rarely depart from their preferred modus operandi, mainly because of the expertise they have developed in fabricating a particular type of IED.In addition to the nature of explosives, the switch mechanism of the IED (how it is triggered) provides additional insights about likely perpetrators. Mechanisms include (1) command-operated (triggered by the terrorist), (2) timer-operated, (3) victim-operated (suitcase bomb, transistor bomb, landmines, etc.).Finally, the mode of carriage and placement of IEDs, whether they are suicide vehicle-borne, vehicle-borne, person-borne, etc complete the intricacies of identifying the ‘bomb signature’ of the terrorist group involved. There are a number of other indicators also in an IED, which cannot be discussed here. The National Bomb Data Centre of NSG is the repository of all bomb blast data in the country and provides expert opinion on the nature and composition of a device.Story continues below this adDeclining trend of IED blastsThis brings us to the next question of the emerging broad trends of IED attacks in the country. Speaking of numbers, there is a declining trend in IED blasts in all conflict theatres as well as in the hinterland. In the Jammu & Kashmir theatre, most IEDs have a combination of explosive mix which includes military, commercial as well as home-made material.The Pulwama suicide attack of 2019 on the CRPF convoy exemplifies this aspect. Nearly 200 kgs of main explosive charge was used in this IED. Approximately 20 kgs comprised RDX which the Jaish terrorists had procured from Pakistan, and the rest of the payload of around 180 kgs consisted of a mix of commercial high explosive (Superpower 90), fertiliser and ammonium powder. Superpower 90, an emulsion explosive, was illegally procured from a mining area in South Kashmir, and ammonium powder and fertiliser (Calcium Nitrate) was purchased locally off-the-shelf.Also Read | Pakistan’s 27th Constitutional Amendment Bill now law: How it makes Asim Munir more powerful, weakens Supreme CourtAnother trend in J&K and also in Punjab is the dropping of pre-fabricated sticky bombs (Magnetic IEDs) through drones from the Pakistan side. The payloads in these devices are comparatively small and comprise military grade high explosives. In recent years, these drone drops have reduced substantially.Story continues below this adIn the Naxal areas again, there is a major decline in IED blasts. The majority of the devices used have commercial explosives as the main charge. Finally, in the hinterland, the only IED blast of note (before Red Fort) was in Rameshwaram Café in Bengaluru in March, 2024, wherein low-explosives were used in the payload.It is evident from the above that jihadi terror outfits, in the recent past have resorted to creating an explosive mix of military grade, commercial-use as well as home-made material to fabricate IEDs.Ongoing cat-and-mouse gameIt is important to understand the source of these explosives.Military grade explosives are usually supplied by Pakistani handlers from across the border through drones or human couriers. While our border management has demonstrably improved over the past few years, the border patrols have to succeed every single time in intercepting caches, while the masterminds have to succeed just once in delivering a large consignment. Hence it is a continuous game of cat-and-mouse to upgrade our surveillance systems and maintain constant vigil.Story continues below this adCommercial explosives and detonators are used under license for mining, road building and construction purposes. The Petroleum and Explosives Safety Organization (PESO), under the Ministry of Commerce, monitors the production, supply chain management, inventory control and last mile usage of these items. Incidentally, India is one of the largest producers of commercial detonators in the world.PESO, over the years, has done a sterling job of ensuring safety standards relating to bulk handling of explosives. But its capacity being limited in terms of reach and manpower; pilferages happen at the level of end users. This happens more so in insurgency-prone areas through coercion, and sometimes even through collusion. This gap in enforcement needs to be addressed.Also Read | How Delhi’s Red Fort blast, first in capital in 13 years, marks a break from recent trendFinally, with regard to extraction of explosives from precursor chemicals and common materials such as fertilisers, the options for a terrorist are endless. However, in India commonly-used fertilisers are not easy to ‘cook’ due to certain in-built safeguards. However, there is a need to clearly identify important precursor chemicals and other items which can be exploited to extract explosives, and make it mandatory for sellers to report bulk purchase of such items to local police stations.Story continues below this adNeed for policy frameworkThe above facts bring to light the need for a holistic National Counter-IED Policy framework. Such a framework should address both strategic and tactical aspects of dealing with this menace, while synergising the efforts of all stakeholders with clearly delineated responsibilities.While it may be of interest to understand the nature of the recent Red Fort blast and whether the IED went off accidentally, it is unwise to speculate since one is not privy to the details of the composition of the IED. But it appears to be a Nitrate-based explosive mix.Finally, no praise is too high for the intrepid doctor-cop of Srinagar, who clinically diagnosed the Jaish posters, conducted a thorough investigation and launched a near flawless operation, resulting in a successful surgery against an entirely new breed of terror module.M A Ganapathy was the Director General of the NSG from 2021 to 2024. He previously served as the DG of Bureau of Civil Aviation Security and DGP Uttarakhand