Ukraine and Russia accused each other of shelling rescuers and evacuees in the flood-hit Kherson region on Thursday as Moscow said its forces fought off a Ukrainian offensive in another part of the front line.

Emergency services were still racing to rescue people stranded by the flood-swollen waters of the Dnipro River, which have forced thousands to flee.

The destruction of a major Russian-held dam on the river on Tuesday unleashed a torrent of water that has left 600 square kilometres of the region under water.

Ukrainian President Volodymyr Zelensky visited the area on Thursday after floods inundated dozens of villages and parts of the regional capital, Kherson.

“I thank the rescuers and volunteers! I thank everyone involved in this work!” wrote Zelensky, who also visited survivors in hospital.

Shortly after the visit, Kyiv said a Russian strike in the centre of Kherson injured nine people including a police officer and two employees of the state emergency service.

Moscow-installed authorities on the other bank of the Dnipro River, which is controlled by Russian forces, said two evacuees were killed by Ukrainian shelling.

The death toll from the flooding reached six as the Moscow-backed administration of Nova Kakhovka, where the dam is located, said five people had died and 41 admitted in hospital.

Ukrainian police said one man had died in a riverside village in the neighbouring Mykolaiv region, also affected by rising water levels.

Two-hour battle

In the neighbouring Zaporizhzhia region, Russia said its forces had fought a two-hour battle with Ukrainian troops in the early hours of Thursday.

Russian Defence Minister Sergei Shoigu said the Ukrainian offensive involved 1,500 soldiers and 150 armoured vehicles.

“Today at 1:30 am (2230 GMT) in the Zaporizhzhia area … there was an attempt to break through our defences,” Shoigu said in a statement.

“The enemy was stopped and retreated after heavy losses,” he said.

Ukrainian officials have said their forces are ready for a long-expected counteroffensive but that there would be no formal announcement when it begins.

Ukrainian Deputy Defence Minister Ganna Maliar said only that Russia was conducting “defensive actions” near the town of Orikhiv in Zaporizhzhia region.

‘Still people in there’

In the Kherson region, Ukrainian rescuers said they were venturing into Russian-controlled areas to save civilians despite the danger.

The area is the estuary of the Dnipro River and is dotted with islands and marshland where the precise location of the front line is sometimes unclear.

Ukrainian authorities have said 30 settlements were flooded, 10 of which lie in territory controlled by Russia on the Dnipro’s eastern bank.

Rescuers used boats and amphibious vehicles to pluck people from flooded areas. Some volunteers were also going out to rescue stranded animals and birds.

One woman, Tetiana Omelchenko, 65, said she had waited two days to be evacuated from her block of flats in Kherson and had to climb through a broken window to reach a rescue boat.

“In my building, the water has reached the third floor and there are still people in there,” she said.

An employee at Kherson’s meteorological agency, Lora Musiyan, waded into the water to mark the level on Thursday morning: 5.33 metres above the norm.

The water was rising more slowly, she said, however: up just 12 cm overnight, while at the peak, the water level had been rising 12-16 cm every half hour.

‘Outrageous destruction’

Zelensky singled out the United Nations and Red Cross for criticism in an interview with Germany’s Bild daily, claiming: “they are not there”.

The Red Cross of Ukraine denied this, saying it immediately began evacuating people and had six crews working and more than 200 volunteers providing humanitarian aid.

Nato Secretary General Jens Stoltenberg said he would chair a meeting Thursday of an emergency coordination panel on the “outrageous destruction”, with Ukraine’s foreign minister Dmytro Kuleba set to participate.

France has also said it will send aid to Ukraine.

The Kakhovka dam provided cooling water for Europe’s largest nuclear plant, Zaporizhzhia, which is under Russian control.

The UN nuclear watchdog, the International Atomic Energy Agency, has said there was “no short-term risk” to the plant.

The dam’s reservoir level has plummeted as water drains out. Ukraine’s state hydroelectric enterprise Ukrhydroenergo said that plants upstream on the Dnipro were reducing capacity to minimise flooding.

Ukraine accuses Russia, whose forces control the dam area, of blowing up the dam, while Russia accuses Ukraine hitting it with artillery.

Ukrhydroenergo said that the dam was most likely mined from the inside.

The emergency service has warned the flood water has dislodged land mines that pose a threat to civilians.

The government has also sounded the alarm over the environmental impact, calling it “a crime of ecocide”.

A Greenpeace campaigner in Kyiv, Denys Tsutsaiev, warned that it could take a decade for some species to recover from the catastrophe and some may not recover at all.

According to the latest information, “at least 500 tonnes of oil was released due to the dam destruction,” the campaigner said, posing a threat to sea mammals and birds.