Esther 9:6 (ESV)

6 In Susa the citadel itself the Jews killed and destroyed 500 men,

Haman still had loyal supporters in the citadel of Susa. Although they lived around the palace and would be well aware of the king’s sentiments, they still attempted to attack the Jews. As a result, the Jews killed five hundred men. (This suggests that the Jews attacked only their attackers, leaving women, children, and bystanders in peace.)