A powerful explosion rocked an ammunition factory near Colleferro, about 40 kilometers (25 miles) southeast of Rome, on Thursday, Italian authorities and local media reported.

Firefighters and police were already at the site responding to a fire when the explosion occurred, according to local media. Italy's Carabinieri police confirmed the blast and said "complex operations" were underway at the facility, without immediately providing further details.

"At this time, the absolute priority is to ensure people's safety and allow all personnel involved in the emergency response to operate under the best possible conditions," Francesco Rocca, president of the Lazio region, said in a statement.

Initial reports by local media said that all workers at the plant were safe, and that the blast may have originated in the plant's powder-pressing department.

Emergency crews, including firefighters and police, responded to the site as the fire continued to burn. Residents reported hearing a loud explosion across the area.

Television footage showed a large plume of smoke rising above the industrial site as emergency crews worked in the area. The blast was reportedly heard from several kilometers away.

The explosion occurred at the former Simmel Difesa plant, which is now operated by KNDS Ammo Italy, part of Franco-German defense group KNDS, according to Italy's ANSA news agency.

The facility manufactures medium- and large-caliber ammunition for land and naval defense systems, as well as solid propellants used in aerospace launch vehicles, according to the company.

KNDS is also among the contractors covered by European Defence Agency framework agreements for the joint procurement of 155 mm ammunition concluded in 2023, according to EU documents.

Further details on the cause of the fire and explosion were not immediately available.