Ukraine's Russian-occupied city of Kherson was cut off from water and electricity supplies Sunday after an air strike and a key dam in the region was also damaged, local officials said.
It is the first time that Kherson -- which fell to Moscow's forces within days of their offensive launched in February -- has seen such a power cut.
"In Kherson and a number of other areas in the region, there is temporarily no electricity or water supply," the city's Moscow-installed administration said on Telegram.
It said it was a "result of an attack organised by the Ukrainian side on the Berislav-Kakhovka highway that saw three concrete poles of high-voltage power lines damaged".
Energy specialists were working to "quickly" resolve the issue, the Russian-backed authorities said, as they called on people to "remain calm".
News of the outage followed reports that the Kakhovka dam in the Russian-controlled region of Kherson was "damaged" by a Ukrainian strike.
"Today at 10:00 (0800 GMT) there was a hit of six HIMARS rockets. Air defence units shot down five missiles, one hit a lock of the Kakhovka dam, which was damaged," Russian news agencies quoted local emergency services as saying.
The RIA Novosti news agency quoted a local Moscow-backed official saying the damage was not "critical".
Ukraine in recent weeks warned that Moscow's forces intended to blow up the strategic facility to cause flooding.
The Kakhovka hydroelectric dam in southern Ukraine was captured by Moscow's forces at the start of their offensive. It supplies Russian-annexed Crimea with water.
- Flooding threat -
For weeks, Russian forces have rained missiles and explosive drones onto Ukraine's infrastructure, as a major Ukrainian ground offensive -- propelled by Western arms deliveries -- has pushed Russian troops back in swathes of the country.
Russian strikes over the past month have destroyed around a third of Ukraine's power stations and the government has urged Ukrainians to conserve electricity as much as possible.
But until now, Ukraine had only rarely struck Russian-held civilian energy infrastructure in territory annexed by Moscow, preferring to target Russian army supply lines.
As Ukraine presses a counteroffensive in the south, Moscow's occupational forces in Kherson have vowed to turn the city into a "fortress".
Russian forces have for weeks organised a civilian pull-out from the Kherson region as Ukrainian troops advance, which Kyiv has called "deportations".
Moscow-installed Kherson governor Vladimir Saldo said he was moving people further into the region or to Russia because of the risks of a "massive missile attack".
The dam's destruction would lead to flooding of the left bank of the Dnipro River, he said.
Ukrainian President Volodymyr Zelensky said last month that Russian forces had mined the Kakhovka hydroelectric power plant with the intent of blowing it up.
Its destruction could cause flash-flooding for hundreds of thousands of people, he warned.
He said cutting water supplies to the south could also impact the cooling systems of the Zaporizhzhia nuclear power plant, Europe's largest.
Meanwhile a Taiwanese man who volunteered to fight in Ukraine has died on the battlefield, Taipei's foreign ministry said, in what is believed to be the first person from the island killed in the conflict.
And in a final address on his visit to Bahrain, Pope Francis on Sunday urged congregants to pray "for Ukraine, which is suffering so much", and for an end to the war.