This can be translated as a statement. Alternate translation: "The nations should not be able to say, 'Where is their God?'" (See: [[rc://en/ta/man/translate/figs-rquestion]])
To shed blood is a metonym for killing innocent people. This can be translated in active form. Alternate translation: "Avenge your innocent servants whom the nations killed where we can see you do it" (See: [[rc://en/ta/man/translate/figs-metonymy]] and [[rc://en/ta/man/translate/figs-rquestion]])