Revelation 9:17-19

 17 And thus I saw the horses in the vision, and them that sat on them, having breastplates of fire, and of jacinth, and brimstone: and the heads of the horses were as the heads of lions; and out of their mouths issued fire and smoke and brimstone.

18 By these three was the third part of men killed, by the fire, and by the smoke, and by the brimstone, which issued out of their mouths.

19 For their power is in their mouth, and in their tails: for their tails were like unto serpents, and had heads, and with them they do hurt.

The description in this passage is probably only supernatural in the sense that angels were loosed for a specific time to allow this to happen and that demons are now free to deceive and inhabit those who dwell on the earth. The entire wording of this judgment makes it fairly clear to me that this is describing a great all out world war between the West and the East.

The fire that comes out of the mouths of the horsemen is every modern weapon of warfare like tanks, and artillery. The tails like serpents that had heads that did harm sound exactly like modern rockets and bombs with warheads. This will be an all out world war using nuclear, chemical and biological warfare and billions will die.