Four Canadian border agents were hospitalized early Friday morning after encountering a potentially contaminating substance at the Peace Bridge in Fort Erie, Ont.
The officers were conducting a secondary examination of a vehicle and its occupants when they became ill after exposure to an unknown substance, a Canada Border Services Agency spokeswoman.
Emergency Medical Services transported all four to Greater Niagara General Hospital in Niagara Falls, Ont., where they were treated and released.
Emergency medical services personnel responded to the bridge at about 6:20 a.m. and transported the officers to the hospital, Niagara Falls Fire Chief Jim Boutelier said. They were given decontaminating showers, examined and treated, he said, adding he also did not know the nature of the substance.
CBSA spokeswoman Diana Scott added her agency also still does not know what substance the officers encountered.
The incident remains under investigation.