Ukraine war: Kyiv 'makes biggest advance in the south since war began'

Key developments to know about from Russia's war in Ukraine:

Kyiv made a major military breakthrough in south Ukraine on Monday, Reuters reports.

Ukrainian troops recaptured villages along the banks of the Dnipro River in southern Ukraine, creating a large front that is forcing Moscow to abandon ground it annexed only days ago.

The advance into the Kherson region was the biggest Kyiv has made since the war began in February, according to Reuters.

It comes off the back of similar breakthroughs in the east that have turned the tide of the war in recent weeks, prompting Russia to mobilise hundreds of thousands of reserve troops.

Monday's advance was confirmed by an official of the Russian-backed administration in Kherson province, which Russia seized early on in the war. 

Vladimir Saldo said that a number of settlements along the river had been captured, reaching as far as the village of Dudchany. This would represent an advance of around 40km (25 miles) in a single day.

"Information is tense, let's put it that way, because, yes there were indeed breakthroughs," Saldo told Russian state television.

Kyiv has so far remained tight-lipped about the situation in Kherson.

In one of the rare images apparently confirming the advance, Anton Gerashchenko, an adviser to Ukraine's interior ministry, posted a photo of Ukrainian soldiers posing with their flag draping a golden statue of an angel.

Gerashchenko said it was the village of Mikhailivka, which would represent an advance of around 20 km (12 miles).

Euronews cannot independently verify these reports.

The head of Russia's Chechen Republic announced on Monday that he would send his teenage boys to fight in Ukraine. 

Ramzan Kadyrov, a staunch ally of Russian President Vladimir Putin, said his three sons -- aged 14, 15 and 16 -- would head into battle in Ukraine on Telegram. 

He made the announcement just days after criticising the Russian military command and calling for the use of nuclear weapons. 

"The time has come [for them] to shine in a real battle, and I can only salute their determination," Kadyrov wrote in a Telegram post on his official channel, referring to his sons named Akhmat, Eli and Adam. 

"Soon they will go to the front line and they will find themselves in the most difficult areas of the contact line," he added. 

The Chechen leader has 14 children, according to his official website, but Russian media say he may have more.