I continue to be amazed that people are still calling this a truck bomb when the videos available clearly show the only truck in the vicinity a considerable distance past the source of the blast and another video that clearly shows the bow of a fairly fast moving boat appear in exactly - that is EXACTLY - the place and time of the blast.
Failure of the Ukrainian regime to claim this coup is not surprising as there are clearly independant Ukranian partisan groups operating freely within Russia (eg that blast at the Navy warehouse yesterday - unless you believe it was yet another careless smoker...)and not necessarily in contact with or under cntrol of Kiev.
Russia is home to hundreds of thousands of native Ukranians and if they conspire to dusrupt whatever they can disrupt here and there Russia has an additional problem in its midst. Apparently random Air Force basearms stores and Naval warehouse explosions within Russia are unlikely to be unconnected with this crisis. I suspect Ukraine has a useful number of cells or sleeper units ingrained into Russian society and if they can cobble together a boat-bomb or other disruptive device then they will do do - independently.
Bless'em.