Ukraine accused Russia of blowing up the dam from the inside in a deliberate war crime. Russian-installed officials gave conflicting accounts, some blaming Ukrainian shelling, others saying the dam had burst on its own.
The Nova Kakhovka dam supplies water to Ukraine's Crimean peninsula and the Zaporizhzhia nuclear plant, both under Russian control.
The destruction of the dam creates a new humanitarian disaster in the centre of the war zone and transforms the front lines just as Ukraine is unleashing a long-awaited counteroffensive to drive Russian troops from its territory.
Russia has controlled the dam since early in the war, although Ukrainian forces recaptured the northern side of the river last year. Both sides had long accused the other of planning to destroy it.
The Russian-installed governor of Ukraine's Kherson region accused Kyiv of striking the dam with missiles to distract attention from what he said were the failures of Ukraine's counteroffensive in the east. However, other Russian-installed officials said the dam had burst on its own due to earlier damage.
Neither side offered immediate evidence proving who was to blame.
Ukraine ambassador says dam blast shows Russia is a 'terrorist state'
Top Ukrainian diplomat Anton Korynevych on Tuesday called Russia a "terrorist state" and blamed it for the destruction of the Nova Kakhovka dam.
"Russia cannot defeat us on the battlefield, so it targets civilian infrastructure to try to freeze us into submission. Just today Russia blew up a major dam," Korynevych, Ambassador-at-large for Ukraine's foreign ministry, said at the International Court of Justice (ICJ) in The Hague.
"It is causing significant civilian evacuations, ecological damages and is threatening the safety of the Zaporizhzhia nuclear power plant. Russia's actions are the actions of a terrorist state, an aggressor," he said.
Korynevych was speaking in opening remarks at the ICJ as hearings began in a case over Moscow's backing of pro-Russian separatists blamed for the down Malaysian Airlines Flight MH17 in 2014.
It was the first time lawyers for Ukraine and Russia met at the ICJ, also known as the World Court, since Moscow launched a full-scale invasion of Ukraine on February 24, 2022. Legal teams with dozens of representatives were sent by each side.
Russian-installed official: Kyiv struck dam to distract from counteroffensive 'failures'
The Russian-installed governor of Ukraine's Kherson region said on Tuesday that Kyiv had struck the Kakhovka dam to deflect attention from what he said were the failures of Ukraine's long-awaited counteroffensive in the east of the country.
In a video posted on Telegram, Vladimir Saldo said that a major evacuation would not be necessary as a result of the dam breach.
TASS cited emergency service as saying that Ukraine had struck the region with Storm Shadow missiles which had been supplied to Kyiv by Britain.
Kremlin: Ukraine sabotaged Kakhovka dam because counteroffensive is faltering
The Kremlin on Tuesday accused Kyiv of sabotaging the Kakhovka hydro-electric dam in the Russian-controlled part of Ukraine to distract attention from a purportedly faltering counter-offensive against Russian forces.
Kremlin spokesman Dmitry Peskov said President Vladimir Putin had been briefed on the situation around the dam, which was breached in the early hours of Tuesday.
"We can state unequivocally that we are talking about deliberate sabotage by the Ukrainian side," Peskov told reporters.
He said the destruction of the dam was intended to deprive Russian-controlled Crimea of the freshwater it receives from the reservoir via the North Crimean Canal and to distract attention from the counter-offensive.
"Apparently, this sabotage is also connected with the fact that, having started large-scale offensive actions two days ago, now the Ukrainian armed forces are not achieving their goals - these offensive actions are faltering."
Asked about Ukrainian allegations that Russia had destroyed the dam, Peskov said: "We can strongly reject this. We officially declare that here we are definitely talking about deliberate sabotage from the Ukrainian side."
Peskov said the sabotage could "potentially have very serious consequences for several tens of thousands of residents of the region."
Reuters