A vast Soviet-era dam in the Russian-controlled part of southern Ukraine was blown on Tuesday, unleashing a flood of water across the war zone, according to both Ukrainian and Russian forces.
The flooding forced villagers to flee and prompted finger-pointing from both sides.
Russia has controlled the dam since early in its 15-month-old invasion, although Ukrainian forces recaptured the Dnipro's northern bank last year. Both sides had long accused the other of plotting to destroy the dam.
Ukrainian President Volodymyr Zelenskyy blamed the destruction on "Russian terrorists".
"The destruction of the Kakhovka hydroelectric power plant dam only confirms for the whole world that they must be expelled from every corner of Ukrainian land," he wrote on the Telegram messaging app.
Russians had "carried out an internal detonation of the structures" of the dam. "About 80 settlements are in the zone of flooding," he said on Telegram.
The Kremlin blamed Ukraine, saying it was trying to distract from the launch of a major counteroffensive Moscow says is faltering.
Unverified videos on social media showed a series of intense explosions around the Kakhovka dam. Other videos showed water surging through the remains of the dam with bystanders expressing their shock, sometimes in strong language.
The Geneva Conventions explicitly ban targeting dams in war because of the danger to civilians.
Hundreds of people were evacuated from settlements along the southern stretch of Ukraine's Dnipro river as flood waters submerged streets, town squares and homes.
It was not immediately clear if anyone had been killed. The White House said it could not say conclusively what caused the destruction of the dam, but spokesman John Kirby said it had probably caused "many deaths".
Abandoned vehicles by a flooded road in Aleshki, The flood occurred after a dam was breached at the Kakhovka Hydroelectric Power Plant. Credit: TASS/Sipa USA
On the Russian-controlled bank of the Dnipro, the Moscow-installed mayor of Nova Kakhovka said water levels had risen to 11 metres. He did not say how high water levels were before the dam burst.
Residents reached by telephone there told Reuters that some had decided to stay despite being ordered out.
This video screen grab shows a flooded area in Novaya Kakhovka, The flood occured after a dam was breached at the Kakhovka Hydroelectric Power Plant. Credit: TASS/Sipa USA
Yevheniya, a female resident, said the water was up to the knees of the Russian soldiers walking the main street in high rubber boots. "If you try to go somewhere they don't allow, they immediately point their machine guns at you," she said. "More and more water is coming every hour. It's very dirty."
The dam, 30 metres tall and 3.2 km long, was built in 1956 on the Dnipro river as part of the Kakhovka hydroelectric power plant.
It holds an 18 km3 reservoir which also supplies water to the Crimean peninsula, annexed by Russia in 2014, and to the Zaporizhzhia nuclear plant, which is also under Russian control.
Poised for counteroffensive
The dam's destruction threatened a new humanitarian disaster in the centre of the war zone and transformed frontlines just as Ukraine prepares a long-awaited counteroffensive to drive Russian troops from its territory.
Russian Defence Minister Sergei Shoigu said his forces had thwarted the first three days of the offensive in battles that had left more than 3,700 Ukrainian soldiers dead or wounded.
Ukraine dismissed the Russian statements as lies but gave no details on the attacks.
NATO Secretary-General Jens Stoltenberg called the dam's destruction "an outrageous act, which demonstrates once again the brutality of Russia's war in Ukraine".
UN Secretary-General Antonio Guterres said the United Nations had no independent information on how the dam was breached, describing it as "another devastating consequence" of Russia's invasion.
The UN Security Council will meet later on Tuesday to discuss the dam at the request of both Russia and Ukraine.
