Suspicious envelope addressed to President Trump intercepted, Secret Service says

A suspicious envelope that was addressed to President Donald Trump was intercepted by the Secret Service Monday, authorities say.

The envelope did not enter the White House, according to the Secret Service.

"The Secret Service can confirm receipt of a suspicious envelope addressed to the President on Oct. 1, 2018," the Secret Service said in a statement. "The envelope was not received at the White House, nor did it ever enter the White House. As a matter of practice, the Secret Service does not comment regarding matters of Protective Intelligence. However, in this instance, we can confirm that we are working jointly with our law enforcement partners to fully investigate this matter. Further, all threats directed towards the President, or any Secret Service protectee, are treated seriously and fully investigated."

This comes as the FBI seized two envelopes suspected of containing ricin, which were delivered to the Pentagon and addressed to Defense Secretary James Mattis and Adm. John Richardson, the Navy's top officer.

The envelopes were discovered at the Pentagon's mail screening center on Monday. However, neither of the envelopes entered the Pentagon as the mail screening facility is on Pentagon grounds, but separate from the main building, according to officials.

These envelopes have been turned over to the FBI for additional testing.

All mail that is being received at the screening facility on Monday is under quarantine and there is no threat to the 20,000 people who work at the Pentagon, Pentagon officials say. No one was ordered to evacuate the facility during the incident.

Two people were taken to the hospital after apparently being exposed to a white powdery substance at Sen. Ted Cruz's office in Houston Tuesday morning, authorities say. The FBI has taken over the investigation into the incident.

Ricin is part of the waste "mash" produced when castor oil is made. According to the Centers for Disease Control and Prevention, if it is made into a partially purified material or refined, ricin can be used as a weapon capable of causing death under certain circumstances.

Information from the Associated Press was used in this report.