Two people have been transported a hospital after being exposed to a white powdery substance on Tuesday at Sen. Ted Cruz's campaign headquarters in Houston, the campaign confirmed to TheBlaze.

Authorities responded to the office building after someone opened an envelope that contained the unknown substance.

Police and hazmat officials evacuated and secured the building while they investigated the scene, Cruz campaign spokeswoman Emily Miller told TheBlaze in an email.

The evacuation order was lifted after the fire department determined there was no hazardous substance found inside the building.

This story will be updated as more information becomes available.