The captives of Babylon were Judeans, not Jews. The Edomites who invaded Judah almost simultaneously to Babylon's destruction of Judah and removing the Israelite Judeans into captivity in Babylon, they become known as Jews, since they inhabit the land of Judah in place of the Israelite Judeans.
Come on peeps, scripture clearly describes all these events in very careful order. Don't run with the brainwashed version of saying they are all Jews, when scripture goes to much trouble to make clear distinction.