Three people were isolated and placed under medical monitoring after a suspicious white powder was discovered on the fifth floor of Trump Tower, a  police spokesperson told Fox 5

The powder was found not far from the Republican front-runner’s campaign offices, NBC New York reported. Authorities are still investigating its source and chemical makeup. 

A police officer is among those isolated, CBS2 reported. The age and gender of the other victims were not available. 

Trump was with his campaign in California when the powder was discovered.