A Pennsylvania hospital is being investigated by state and federal authorities after a review found that security guards used stun guns on unruly patients four times since 2008.

The Morning Call of Allentown says that a state Department of Health report that was completed in October shows the use of stun guns was against regulations and threatened the health and rights of patients at Lehigh Valley Hospital.

The hospital told the newspaper that the incidents were "law enforcement" matters and in no way "related to patient restraint in the normal course of care."

The state report also says that as of Oct. 15, security guards at the hospital were no longer using the devices.