Key Takeaways
- Military-grade explosives suspected in Monday’s blast based on damage scale
- PETN, semtex, RDX, and ammonium nitrate fuel oil under investigation
- Forensic teams examining 42 exhibits from the blast site
- Complete clarity on explosive type expected within days
NEW DELHI: Investigators suspect military-grade explosives caused Monday’s devastating blast, with forensic analysis pointing toward powerful substances like PETN, semtex, or RDX. The scale of damage and casualties indicates high-grade materials were used in the attack.
Forensic teams have collected 42 exhibits from the blast site, including the i20 car’s tyres, chassis, CGC cylinder, bonnet parts, and various residue samples. These will help determine the exact explosive materials used in the incident.
Explosives Under Scrutiny
Investigators have sought forensic opinion on whether PETN, semtex, or RDX could have been deployed. The initial assessment also suggests possible use of ammonium nitrate fuel oil with detonators.
Pentaerythritol tetranitrate (PETN), a major semtex ingredient, is particularly concerning. “PETN is quite stable and detonated either by heat or a shock wave. A car can be destroyed in around 100 grams. Most importantly, neither PETN nor semtex inherently require pellets or shrapnel to act as an explosive and the material itself is enough to cause immense damage through detonation,” said an officer.
This colorless explosive is notoriously difficult to detect and requires minimal quantity compared to other chemicals, making it a terrorist favorite. The 2010 transatlantic air freight bomb plot involved PETN concealed in a printer cartridge.
Ammonium Nitrate and Historical Precedent
Ammonium nitrate fuel oil produces a supersonic shock wave that releases energy at extremely high rates, creating powerful blast effects. The substance is widely available for industrial use but easily weaponized.
In the 2011 Delhi High Court blast, forensic experts initially believed ammonium nitrate mixed with PETN was used, though the home ministry later confirmed RDX involvement.
Investigators suspect a sophisticated detonation system triggered Monday’s explosion, possibly using a watch with button batteries to build the circuit. Complete clarity on the explosive type is expected within days as lab testing continues.
