More than 1.5 million people in the southern Ukrainian city of Odesa have been left without power after Russian drone attacks on power generation infrastructure, President Volodymyr Zelensky said in a video address on Saturday.

All non-critical infrastructure in the Ukrainian port of Odessa was without power after Russia hit two energy facilities with Iranian drones, officials said on Saturday and said the damage could take months to repair.

In a video address, Zelenski said that there is a large deficit in the production of electricity.

Since October, Moscow has been targeting Ukraine’s energy infrastructure in large waves with missiles and drones, and Kiev admitted on Friday that every thermal and hydroelectric plant in the country has been damaged.

The regional administration said people who rely solely on electricity in their homes should leave. Officials said Russian strikes hit key power lines and equipment in the early hours of Saturday.

“According to preliminary forecasts, it will take much longer to restore energy facilities in the Odesa region than after previous attacks,” the administration said.

“We are not talking about days, but about weeks, and possibly two to three months,” the post on Facebook said.

Kiev says Russia has launched hundreds of Iranian-made Shahed-136 drones at targets in Ukraine and describes the attacks as war crimes and for their devastating effect on civilian lives. Moscow claims that the goals are militarily justified.

Ukraine’s Prosecutor General’s Office said two power plants in the Odesa region were hit by Shahed-136 drones.

Ukraine’s armed forces said on Facebook that 15 drones were sent to targets in the southern Odesa and Mykolaiv regions and that ten of them were shot down.

Tehran denies supplying Moscow with drones. Kiev and its Western allies claim that this is a lie.

Odessa, Ukraine’s largest port city, had a population of more than 1 million before the February 24 Russian invasion.