Military‑Grade Explosives Suspected in Delhi Blast; Forensics Probe Underway

New Delhi: Investigators are probing whether military‑grade explosives were used in the powerful car blast near the Red Fort on Monday evening. While forensic teams and the NSG explosives unit continue laboratory tests, the nature and composition of the explosive remain unconfirmed. Preliminary assessments, however, have raised concerns that high‑order military explosives or a sophisticated detonation system may have been involved.

Forensics collecting key evidence
Teams collecting evidence at the scene have gathered around 42 samples — including fragments from the I‑20 car’s tyres, chassis, bonnet and the CGC cylinder — which are now undergoing detailed analysis in national laboratories. Officials say laboratory testing of residues and fragments will be decisive in identifying the exact explosive used.

Investigators weigh several possibilities
Sources indicate investigators have asked whether substances such as PETN, Semtex or RDX could have been used. Preliminary traces consistent with ANFO (ammonium nitrate fuel oil) and detonators have also been reported, but formal confirmation is awaited. ANFO — a commercially available fertilizer‑derived mixture — is widely known for bulk IED use because it is cheap and easy to source, while PETN, Semtex and RDX are military‑grade or high‑power explosives that require more sophisticated sourcing and handling.

What PETN and other high‑end explosives mean

• PETN (Pentaerythritol Tetranitrate) is a powerful, stable explosive often found as a primary component in Semtex. It is prized by attackers because very small quantities (even around 100 grams) can cause catastrophic local damage and it can be concealed as an almost colourless crystal. PETN and Semtex do not always require a heavy metal casing or large shrapnel to create lethal effect.
• RDX is another high‑order military explosive with a high detonation velocity; it is frequently used in military munitions.
• ANFO, by contrast, relies on a fuel‑oxidiser reaction (ammonium nitrate plus fuel oil) and produces a powerful supersonic shock wave when properly confined and detonated — making large ANFO charges particularly destructive in bulk.

Detonation system under scrutiny
Investigators say the device apparently incorporated a proper initiation/ detonator system and may have used timing or battery‑based circuitry to trigger the blast. Forensics teams are therefore also examining recovered electronic components and wiring to reconstruct how the device was armed and activated.

Past precedents and the path ahead
Officials note past high‑profile cases have yielded mixed findings — early forensic reads can point toward different compounds until lab results are final. Authorities expect clearer answers in a few days once laboratory testing of the 42 samples is complete. Meanwhile, investigators continue to trace explosives supply chains and any links to organised groups or cross‑border sources.