A fire broke out on Monday at the Uralmash factory, a large heavy industry enterprise, in the Russian city of Yekaterinburg, Russia's emergencies ministry said.

The area of ​​the fire has reached 4,000 square meters, Russia media said, with videos posted on social media showing large volume of black smoke billowing into the sky.

It's not immediately clear what caused the fire and there's no information on casualties yet. 

(With input from agencies)