Revelation 9:13-16

13Then the sixth angel sounded his trumpet, and I heard a voice from the four horns of the golden altar before God 14saying to the sixth angel with the trumpet, “Release the four angels who are bound at the great river Euphrates.”

15So the four angels who had been prepared for this hour and day and month and year were released to kill a third of mankind. 16And the number of mounted troops was two hundred million; I heard their number.