Revelation 6:9-11

9 When he opened the fifth seal, I saw underneath the altar the souls of those who had been killed for the word of God, and for the testimony which they held.
10 They cried with a loud voice, saying, "How long, Master, the holy and true, do you not judge and avenge our blood on those who dwell on the eretz?"
11 There was given to each one of them a white robe. It was said to them that they should rest yet for a little time, until their fellow servants and their brothers, who would also be killed even as they were, had been fulfilled.