Russian authorities said on Tuesday they have closed a criminal investigation into the armed rebellion led by mercenary chief Yevgeny Prigozhin, with no charges against him or any of the other participants. The Federal Security Service (FSB), said its investigation found that those involved in the mutiny “ceased activities directed at committing the crime” so the case would not be pursued.

The announcement was the latest twist in a series of stunning events in recent days that have brought the gravest threat so far to President Vladimir Putin’s grip on power amid the 16-month-old war in Ukraine. Over the weekend, the Kremlin pledged not to prosecute Prigozhin and his fighters after he stopped the revolt on Saturday, even though Putin had branded them as traitors.