KYIV: Fighting was raging on Friday in southern Ukraine, with observers seeing the combat as the opening phase of Kyiv's long-expected offensive.
Ukraine has said little about the clashes but Moscow reported repelling attacks in the Zaporizhzhia and eastern Donetsk areas with ground and air forces.
That fighting came as the human cost climbed after the destruction of the Kakhovka dam unleashed flooding along the Dnipro River in a different part of Ukraine's south, where a massive explosion was detected as the dam collapsed.
Moscow says clashes have intensified since Thursday in the Zaporizhzhia region, particularly around the small town of Orikhiv and towards the larger city of Tokmak, around 40 kilometres to the south in Russian-occupied territory.
A Ukrainian military success in the Zaporizhzhia region would enable its forces to break through the land bridge that connects Russia with the Crimean peninsula it annexed from Ukraine. This would be a major reverse for Moscow.
But the Russian army in recent months has strengthened its front lines in the region, digging kilometres of trenches and fortifying its defences.
The Russian army said it had pushed back four attacks — "carried out by forces of up to two battalion tactical groups, reinforced with tanks" — near the villages of Levadnoye in the Zaporizhzhia region and in the village of Novosleka in the Donetsk region.
It said it had used troops and air force to repel two attacks near Novodanilovka and Malaya Tokmachka in the Zaporizhzhia region.
The uptick of fighting in the south has been seen by many observers as a sign that the counter-offensive is already happening, or is about to start.
Kyiv, however, said the main centre of combat was still in Ukraine's east, while providing few details on the situation in the south.
"The enemy continues to concentrate its main efforts on the Lyman, Bakhmut, Avdiivka and Maryinka directions", said Ukrainian Deputy Defence Minister Ganna Malyar, referring to eastern cities where fighting has been raging for months.
Russia has reported "heavy" Ukrainian losses, but that information is impossible to verify.
Ukrainian officials have said their forces are ready for a long-expected counteroffensive but that there would be no formal announcement when it begins.
More casualties of dam breach
Parallel to the fresh fighting, the destruction of the major Russian-held dam on the Dnipro river on Tuesday left 600 square kilometres of the region under water.
Emergency services were racing to rescue people stranded by the flood-swollen waters of the Dnipro, which have forced thousands to flee.
Russian-installed authorities in southern Ukraine on Friday reported more casualties from the flood triggered by the dam's destruction, and said the water could keep rising for more than a week.
"Unfortunately, there are casualties. ... Their number has grown to eight people," the Moscow-installed head of the Kherson region, Vladimir Saldo, said on Telegram.
The water, which flooded 22,273 homes in 17 settlements, could "keep rising for up to ten days".
More than 5,800 people were evacuated since the flood was unleashed on Tuesday, Saldo said, including 243 children.
At least five people died and 13 are missing in flooding after the breach, Ukraine's Interior Minister Igor Klymenko said Friday in a social media post.
Dam 'not bombed'
Ukraine and Russia have traded blame for the destruction of the Kakhovka dam, but EU foreign policy chief Josep Borrell said that "everything indicates" Moscow is behind the breach.
"The dam was not bombed. It was destroyed by explosives installed in the areas where the turbines are located. This area is under Russian control," Borrell told Spanish public television.
Norway's seismological institute said it had detected "an explosion" at the site and time the dam was destroyed, supporting suggestions the breach did not occur as a result of damage incurred during months of heavy bombing.
Ukrhydroenergo, the dam's operator, said it was most likely mined from the inside.
Ukrainian authorities said water levels in a reservoir which had been created by the Kakhovka dam had fallen "below the critical point of 12.7 metres (42 feet)".
They said the reservoir was no longer able to supply households and the cooling ponds at the Zaporizhzhia nuclear power station, Europe's largest.
However late Thursday the International Atomic Energy Agency (IAEA) said the nuclear plant was continuing to receive water from the reservoir after the dam was damaged.
The plant's six reactors have been shut down but they still need cooling water to ensure there is no nuclear disaster.
Ukraine meanwhile called on Europe to double power supplies to two gigawatts.
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".