German Chancellor Angela Merkel's Christian Democrats suffered a defeat in two of three states in regional polls Sunday, exit polls showed, while the populist AfD captured seats in all three amid a stunning surge of support.

Exit polls published as voting closed at 1700 GMT showed the CDU scoring a historic low of 27.5 percent in stronghold Baden-Wuerttemberg, behind the Greens.

The anti-migrant AfD meanwhile obtained double-digit scores in all three, garnering as much as 23 percent of the vote in the eastern state of Saxony-Anhalt.