The death toll from an explosion at a plastics manufacturing facility in Russia has increased to 13, according to a statement from the Chelyabinsk regional administration on Monday.

The explosion took place last Wednesday evening at the Plastmass plant located in Kopeysk. This facility, which manufactures artillery ammunition for the Russian military, is under Western sanctions.

It remains uncertain whether the blast was caused by sabotage or any intentional act.

Chelyabinsk region Governor Alexei Teksler has, however, dismissed the possibility that drone strikes were involved in the tragic event.

As per the latest information from the regional administration, the remains of all 13 victims have been recovered.

Emergency responders are concentrating on locating additional remains and are engaged in a lengthy identification process, the statement noted.

Previously, Teksler mentioned that 11 individuals were still unaccounted for. With the confirmation of the 13th fatality, the number of missing persons is now likely down to 10.

Currently, four patients are receiving care at the regional hospital, while two others have been transferred to a specialized burn center in Nizhny Novgorod for advanced treatment; additional patients are being treated on an outpatient basis.