Revelation 11:4-6

The two witnesses are the two olive trees and the two lamps that stand before the Lord of the earth. If anyone tries to harm them, fire comes out of their mouths and destroys their enemies; and in this way whoever tries to harm them will be killed. They have authority to shut up the sky so that there will be no rain during the time they proclaim God's message. They have authority also over the springs of water, to turn them into blood; they have authority also to strike the earth with every kind of plague as often as they wish.