Ukrainian President Volodymyr Zelensky announced the resignation of his powerful chief of staff, Andriy Yermak, whose residence was searched earlier in the day by anti-corruption investigators.

Volodymyr Zelensky’s former chief of staff said he will go to the front line and fight against Russia, just hours after resigning from his position amid a corruption probe.

The statement did not disclose the reason for the raids, but the raid comes just two weeks after the two agencies announced a sweeping investigation into a kickback scheme concerning Ukraine’s critica...