Explosion Rips Through Ammunition Plant Near Rome; Summer Shutdown Averts Casualties

Colleferro, Italy — A powerful explosion tore through an ammunition factory southeast of Rome on Thursday afternoon, throwing a plume of smoke visible for kilometres and shaking the surrounding town. No injuries were reported. The reason, according to the local mayor, was the calendar.

The blast struck the KNDS Ammo Italy plant in Colleferro, in the Lazio region, shortly after 15:00 local time. It followed a fire in the facility's powder-pressing department, and detonated while firefighters and Carabinieri were already on site responding to the blaze.

"It would have been a tragedy" had the explosion not occurred during the summer holiday period, when the plant was largely closed, Colleferro mayor Giulio Calamita told reporters, according to Reuters. Calamita described a huge scare in the town but confirmed no one was hurt. Reports put the on-site workforce at the time at roughly 20 to 24 people, a fraction of normal staffing.

Residents across Colleferro and neighbouring municipalities reported a loud detonation. Images circulating on social media showed a mushroom-shaped cloud rising above the industrial area.

Police and ten firefighting crews, supported by a helicopter dropping water, responded as the fire continued to burn and spread into nearby vegetation, the Associated Press reported. Officials said the blast appeared to have originated in the powder-pressing department — the section where propellants and explosives are processed.

Francesco Rocca, president of the Lazio region, said he was monitoring events with great concern and that the immediate priority was ensuring the safety of personnel and emergency responders. Traffic on nearby roads was restricted.

Full inspection of the site was initially impossible because of the intensity of the fire. Emergency crews worked into the evening to extinguish remaining flames.

The Colleferro facility opened in 1912 and was formerly known as Simmel Difesa. It is now owned and operated by KNDS Ammo Italy, a subsidiary of KNDS, the Franco-German defence group formed from the merger of France's Nexter and Germany's Krauss-Maffei Wegmann.

The plant produces medium- and large-calibre ammunition for land and naval defence systems, along with propellant powders and solid propellants used in aerospace launch vehicles.

KNDS said the circumstances of the incident were being investigated and assessed by teams on site. The Velletri prosecutor's office has opened a file, with an industrial accident the initial working hypothesis.

The incident lands in the middle of Europe's attempt to rebuild an ammunition industrial base it spent three decades allowing to shrink.

Since 2022, European producers have been scaling up output of 155mm shells and related munitions under framework contracts drawing in multiple industrial groups, KNDS among them. That expansion means running energetic-material lines closer to their limits, at higher throughput, often in facilities built for a different era of demand. Incidents that produce no casualties still raise the question of what safety margins look like under that pressure.

KNDS is also directly exposed to the Ukrainian supply chain. The group has positioned itself as a significant partner to Kyiv and opened a subsidiary there in October 2024 to repair Western-supplied equipment.

Colleferro's mayor moved quickly to head off speculation, urging residents not to circulate false information — specifically citing renewed sharing of claims relating to a 2007 accident at the site. No official has suggested the Thursday blast was anything other than an accident, and the preliminary indication points to a failure in a powder compactor.

The cause has not been established. Investigators have not said what triggered the initial fire, nor whether the explosion was a single event or a sequence — early wire copy referred variously to one blast and to multiple explosions.

Also unresolved: the extent of structural damage, whether production at the site can resume and on what timeline, and whether any of KNDS's delivery commitments are affected. The company has not quantified the loss.