A factory explosion in Ryazan, Russia, left at least 20 people dead and 134 injured.

Local emergency services reported on Monday that at least 20 people had died and 134 more had been injured in an unexplained explosion that occurred at a production facility in the Ryazan region of Russia last week.

The governor of the Ryazan region, which is located just southeast of Moscow, Pavel Malkov, stated on Friday that a fire that started inside a factory workshop was the cause of the tragedy. However, it remained unclear from Russian media accounts what the factory was manufacturing or what caused the fire. Other than efforts to locate and care for the injured, official Russian agencies provided no information.

“As of August 18, 20 people died as a result of the emergency incident,” the local emergency service headquarters said in a post on Telegram.

“There are 134 injured, of which 31 patients are in hospitals in Ryazan and Moscow , while 103 patients are undergoing outpatient treatment.”