Revelation 6:8-11

8And I saw: and behold, a pale horse, and he that sat upon it, his name [was] Death, and hades followed with him; and authority was given to him over the fourth of the earth to slay with sword, and with hunger, and with death, and by the beasts of the earth.

9And when it opened the fifth seal, I saw underneath the altar the souls of them that had been slain for the word of 1God, and for the testimony which they held;

10and they cried with a loud voice, saying, How long, O sovereign Ruler, holy and true, dost thou not judge and avenge our blood on them that dwell upon the earth?

11And there was given to them, to each one a white robe; and it was said to them that they should rest yet a little while, until both their fellow-bondmen and their brethren, who were about to be killed as they, should be fulfilled.