There have been divisions nearing coup in Russia since the breakup. Yeltsin's famous storming of the Duma being just one. Another was near the end of the Kosovo war when the Butcher of Chechnya was appointed. That put an end to the idea of a coup then by what became Putin's government - they knew that general would bomb Moscow if ordered. A lot happened that May after Yeltsin's people finally figured out what was going on.

I'd view this as a kind of continuation housecleaning by the "forces of clean" (AKA Putin's boys) with posturing by the "forces of crime". For what it's worth, the drug administration is corrupt as hell. How do you think they supported themselves the last 17 years? (By the way, the kosovo war was a bonus baby for that part of the FSB, because it hurt the drug pipeline into Europe through Albania that Osama's boys were running.)