Commissario
Again unfortunately that's probably bird strikes.
Both engines at once suggest it's not a maintainance fault, and the pop pop pop type effect IIRC indicates something has happened to the compressor/turbine and the most common thing to do that especially to multiple engines at once is something entering the intakes from outside, and that is most commonly birdies.
Still not good for Russian aviation as that's likely two complete engines out of action as it likely requires a thorough inspection and overhaul with at the least some replacement parts - they may be able to fly it again without replacing some bits that might be routinely done (and required if going by the manufacturers book), but if they do they'll be flying with some now very suspect engines.
Russia is basically facing all the "normal" aviation issues, but few parts to get aircraft back up and running again, so whilst this probably wasn't a failure due to maintenance, it is going to be much harder to fix than it would normally be as under normal circumstance the operator would likely have a replacement pair of engines fitted within a few days, if not over night as they keep spares specifically for this situation.
