A Hazmat team responded to the federal courthouse in downtown Miami Friday for a possible white powder incident, fire officials said.
Miami Fire Rescue officials said they responded the building at 400 North Miami Avenue for six possible patients who were exposed to the unknown substance.
The six employees were checked out and medically cleared, officials said.
Authorities are still trying to determine what the substance was. No other information was immediately known.
Check back with NBC 6 for updates.