About half a million residents in the region of Odessa in Ukraine are experiencing a major power outage after an electrical substation accidentally caught fire, officials said on Saturday. 

"The situation is complex, the scale of the accident is significant," Prime Minister Denys Shmyhal said on Telegram, adding that the critical infrastructure had been damaged several times due to Russian strikes.

According to Odessa governor Maksym Marchenko, the accident is a "serious" one and the head of state-run electricity grid operator Ukrenergo Volodymyr Kudrytskyi and energy minister Yaroslav Demchenkov were sent to the city. 

"A number of generators will be delivered to the region of Odessa within the next 24 hours," he said.

"We expect the first generators to arrive tonight."

Russia has been targeting Ukraine's infrastructure in response to the bombing operation that destroyed part of the Crimean Bridge, which Russia blamed Ukraine for carrying out. 

Read more: Satellite images show deterioration of Ukraine's power grid

On January 14, Marchenko said that a Russian missile had hit a critical infrastructure facility in the Ukrainian region of Odessa.

Although he mentioned that no casualties were reported in the attack, he did not specify exactly what infrastructure had been targeted.

On January 15, the head of Ukrainian utility YASNO (D.Solutions), Sergey Kovalenko, said that Ukraine's power grid was suffering from a massive power deficit following Russia's missile strikes on Saturday which targeted crucial infrastructure all across the nation. 

Kovalenko added that the impact of the damage was so severe that the Ukrainian national energy company Ukrenergo cut consumption volumes throughout the country, including in the Kiev region.

Read more: US funds $53 M to rebuild Ukraine's national power grid