Is our new head of department a bully?

I am an HR manager for a financial services firm. Since the appointment of a new departmental manager three months ago there has been an increase in sickness absence among her team. The manager was brought in to increase performance in a team that was not, according to senior management, delivering all it should. While performance and productivity levels are picking up, I do think there is an issue with her leadership style, which many staff have interpreted as bullying. Commercially, she’s having the right impact on the bottom line but I am worried about the impact she’s having on people, and the long-term damage this might do.