Operations have resumed at the Ukrainian Black Sea port of Odesa after Russia used Iranian-made drones to hit energy facilities in the city, reports BBC News.

The port in the south of the country was closed after strikes on December 10 left 1.5 million people and all non-critical infrastructure without power. Ukraine's president said it could take days to restore electricity, with sub-zero temperatures expected this week.

Odesa is one of three ports being used to ship grain under a UN-brokered deal.

The agreement, mediated by Turkey and the UN, allows Ukrainian products to be transported safely to the rest of the world. The deal has helped bring down soaring global food prices.

Although operations at Odesa port were briefly stopped on December 11, Ukraine's agriculture minister said grain exports would not be suspended.

In total, Russia launched 15 Iranian-made drones at the regions of Odesa and neighboring Mykolaiv, 10 of which were shot down, Ukraine's armed forces said.