Kyiv: More than 1.5 million residents of Odesa in Southern Ukraine are left without power after Russian drones hit the region's energy supplies.
Ukraine's President Volodymyr Zelenskyy described the situation as 'very difficult', according to Reuters.
Alongside home-made ones, Russia used two Iranian-made drones to hit two energy facilities in Odesa, plunging the city into darkness.
Meanwhile, the United Nations warned of Russia and Iran expanding their ties.
The US also said that the ties between Russia and Iran developed into a fully-fledged defence partnership.
In a video address on Saturday, President Zelensky reported of a "significant" fall in power being generated, adding that it would take days before electricity is restored.
"Due to the scale of the damage all users in Odesa except critical infrastructure have been disconnected from electricity," Odesa's mayor, Gennadiy Trukhanov, reportedly said on Facebook.
People of Odesa are facing the worst situation of having to fight Russian forces while grappling with energy shortage.
Ukraine's armed forces said Russia launched 15 drones against Odesa and Mykolaiv, leading to chaos.
Officials reportedly said the drone attacks disrupted key transmission lines and equipment in the early morning on Saturday.
Showing its endurance, Ukraine attacked occupied Melitopol, which is a strategically located city in the country's southeast, according to Reuters.
Ukraine is fighting back in the midst of Russia's repeated to use of nuclear weapon in its effort to conclude the war.