UNCONFIRMED discussion on Russian social media sites suggest linghtning strike and total electric failure (including loss of communications) on climbout, bounced twice on landing, on third touchdown MLG failed and fire broke out. 'Sources' at airport now speak of 12 casualties in rear rows.
Appears to be a rather poor performance from the side of ARFF, no fire trucks visible for at least 90 seconds following door opening, all this with a known emergency (even if there was no communications with the aircaft, twr should have raised the alarm on seeing the aircraft returning).