A massive explosion has ripped through a gunpowder factory, killing at least 20 people and injuring 134. The enormous blast happened at the Elastik synthetic fibre plant located near the Russian village of Lesnoy in southeast Ryazan province.

The factory produces weapons and explosives for Putin's army fighting in Ukraine. The force of the explosion completely destroyed four factory buildings, which included production facilities and a gunpowder warehouse. Reports claim that around 300 tonnes of gunpowder went up in flames, and 600 units of 152mm artillery shells were wiped out.

The explosion occurred after a fire broke out at the industrial complex, the cause of which has not yet been confirmed. Anonymous emergency sources told RIA Novosti the fire may have been caused by safety violations.

Video images shot by residents in the village show the factory consumed by huge flames, with a thick column of black smoke rising skywards.

Further footage released to social media channels by witnesses at the scene shows the remains of the destroyed buildings.

Lesnoy village is 65 kilometres (40 miles) southeast of Ryazan and 250 kilometres (155 miles) southeast of Moscow.

The region's governor, Pavel Malkov, posted a message to his Telegram channel saying the region would mark the tragic deaths. "Flags will be lowered on the territory of the whole region, he said.

He later added: "As of 7.00 Moscow time on August 18, 20 people have died. There are 134 injured, including 31 patients in hospitals in Ryazan and Moscow and 103 patients receiving outpatient care."

A criminal investigation into the explosion has been opened by Russian investigators.

This is the second fatal explosion at the Elastik factory since October 2021, when 17 people were killed in a workshop operated by explosives producer Razryad.

Elastik belongs to the state defence conglomerate Rostec, which brings together a range of companies supplying industrial or high-tech products to the civilian and military sectors. Local media said the factory went bankrupt in 2015 and that its workshops were used by other explosives makers.