Smoke out of portholes. Hangar door open (perhaps to get a helicopter off ship).

All of these may be indications of attempts at getting help, or perhaps air, to sailors trapped below.

So, would I characterize this as the result of ammo cooking off, like Russia said? No.

Neptun attack? Most likely. The heaviest damage is clearly at exactly amidships.

Could it be an equipment fire? Possible. Doesn't explain reports of detonations.

https://twitter.com/vcdgf555/status/1515829226749845510

https://twitter.com/vcdgf555/status/1516077273455104002

Moskva listed 10 degrees to port (flood below), had considerable fire below decks in her engine compartments (black smoke rising at funnel).

https://twitter.com/vcdgf555/status/1515827841186742274