If true, it could suggest the threat posed by Yevgeny Prigozhin has not been fully defused and the Kremlin is treading carefully.

Over the last year, the U.N.’s atomic watchdog repeatedly expressed alarm over the possibility of a radiation catastrophe like the one at Chernobyl after a reactor exploded in 1986.

Troops were given a morale boost last week by an armed rebellion that posed the most significant threat to President Vladimir Putin’s power in more than two decades.

It was the latest bombardment of a Ukrainian city, a tactic Russia has used heavily in the 16-month-old war.

The march on the capital by Wagner troops led by Yevgeny Prigozhin and the late-night deal that eventually halted it severely dented Putin’s reputation as a leader who is willing to ruthlessly punish anyone who challenges his authority.

After the deal was reached, Yevgeny Prigozhin said he was ordering his troops to halt their march on Moscow and retreat to field camps in Ukraine, where they have been fighting alongside Russian troops.

Some see Putin’s failure to squelch the infighting as a sign of potential shifts in Russia’s political scene that set the stage for more internal battles.