A massive explosion has been reported at a major Italian manufacturer of medium- and large-caliber ammunition, formerly known as Simmel Difesa. The plant operates in Colleferro and Anagni, near Rome.

Local Italian outlet Sky TG24 reports: 

Fire and explosion at Colleferro, in the facility of the former Simmel Difesa, currently owned by KNDS Ammo Italy. The company, located in the Quarto Chilometro area, along via Latina, between Colleferro and Artena, produces medium- and large-caliber ammunition for land and naval defense, as well as solid fuels for aerospace launch vehicles. 

The incident is said to have occurred in the powder pressing department. A loud boom was distinctly heard by residents in the area, triggering the alarm.

Incendio ed esplosione a Colleferro, nello stabilimento dell’ex Simmel Difesa, attualmente di proprietà della KNDS Ammo Italy. L’azienda, che si trova nell’area del Quarto Chilometro, lungo via Latina, tra Colleferro e Artena, produce munizioni di medio e grosso calibro per la… pic.twitter.com/fa7NaSFFtA

— Sky tg24 (@SkyTG24) August 13, 2026

Separately, local media outlet Italia 24H Live posted footage on X that appears to capture the moment the explosion rocked KNDS Ammo Italy. 

Incendio ed esplosione a Colleferro, nello stabilimento dell’ex Simmel Difesa, attualmente di proprietà della KNDS Ammo Italy. L’azienda, che si trova nell’area del Quarto Chilometro, lungo via Latina, tra Colleferro e Artena, produce munizioni di medio e grosso calibro per la… pic.twitter.com/fa7NaSFFtA

— Sky tg24 (@SkyTG24) August 13, 2026

For context, KNDS Ammo Italy produces: 

Complete ammunition ranging from 25mm to 155mm
Naval rounds, particularly 76mm and 127mm ammunition for Leonardo/Oto Melara guns
Medium-caliber ammunition for land, naval and air-defense applications
Artillery ammunition, including 155mm shells
Propellant powders and charges
Explosives and warheads
Proximity and programmable fuzes
Combustible cartridge cases and metal components
Missile components
Ammunition inspection, refurbishment and demilitarization services

Developments remain scant, and officials have yet to disclose the cause of the explosion, the extent of the damage or which production lines, if any, were affected. Against a backdrop of elevated concern over the Russia-Ukraine conflict’s expanding geographic footprint, the explosion warrants scrutiny. Officials have yet to disclose whether the blast was linked to sabotage or hostile action. 

Ending the streak? 

KNDS Ammo Italy is also Italy’s largest producer of medium- and large-caliber ammunition and a preferred supplier for Leonardo/Oto Melara naval guns.

Any supply disruption would have great exposure to: 

76mm and 127mm naval ammunition, including programmable and proximity-fuzed rounds used for air and missile defense
Specialized anti-air and anti-drone ammunition
155mm ammunition and modular propellant charges
Fuzes, explosives and missile components supplied to other weapons manufacturers

Let’s get back to the US, where, in late 2025, Accurate Energetic Systems, a key defense contractor and manufacturer of high explosives for the military, suffered a massive explosion.  

Stockpiles and potentially other KNDS plants could cover any outage at KNDS Ammo Italy. A prolonged disruption affecting explosives, propellant or fuze production would be more serious because alternative ammunition must be qualified for specific guns and fire-control systems. That process can take many months.