Then I heard a loud voice from the temple saying to the seven angels, "Go and pour out the bowls of the wrath of God on the earth."
So the first went and poured out his bowl upon the earth, and a foul and loathsome sore came upon the men who had the mark of the beast and those who worshiped his image.
Then the second angel poured out his bowl on the sea, and it became blood as of a dead man; and every living creature in the sea died.
Then the third angel poured out his bowl on the rivers and springs of water, and they became blood.
And I heard the angel of the waters saying: "You are righteous, O Lord, The One who is and who was and who is to be, Because You have judged these things.
References for Revelation 16:5
For they have shed the blood of saints and prophets, And You have given them blood to drink. For it is their just due."
References for Revelation 16:6