A surprising rebellion erupted in Russia on Friday by the head of the Wagner mercenary group, who accused the Russian military of targeting his Wagner forces in Ukraine with airstrikes and artillery even though they are meant to be fighting on the same side.

The rebellion has triggered the gravest domestic crisis for Russian President Vladimir Putin since the Russia-Ukraine conflict broke out more than one year ago.

Yevgeny Prigozhin, the mercenary boss, has been a close ally of the president. He announced earlier that his Wagner fighters had crossed the border into Russia's Rostov from Ukraine and were prepared to go "all the way" against Moscow's military. He also vowed that he and his men would destroy anyone who stood in their way.

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