Exodus 7:23

“Then You performed signs and wonders against Pharaoh, Against all his servants and all the people of his land; For You knew that they acted presumptuously toward them, And made a name for Yourself as it is this day.

And the second angel sounded, and something like a great mountain burning with fire was thrown into the sea; and a third of the sea became blood,

These have the authority to shut up the sky, so that rain will not fall during the days of their prophesying; they also have authority over the waters to turn them into blood, and to strike the earth with every plague, as often as they wish.