Revelation 9:14-15, 20

It said to the sixth angel who had the trumpet, “Release the four angels who are bound at the great river Euphrates.” And the four angels who had been kept ready for this very hour and day and month and year were released to kill a third of mankind.

The rest of mankind who were not killed by these plagues still did not repent of the work of their hands; they did not stop worshiping demons, and idols of gold, silver, bronze, stone and wood—idols that cannot see or hear or walk.