How to identify and report a suspicious package

The Secret Service on Wednesday said it had intercepted packages addressed to former Secretary of State Hillary Clinton and former president Barack Obama with "potential explosive explosive devices."

» RELATED: Explosive devices: Packages sent to Clintons, Obamas, CNN

CNN's Time Warner Center headquarters in New York also reported its office was evacuated Wednesday morning due to a suspicious package. The package was addressed to former CIA Director John Brennan, according  to city and local law enforcement officials. The New York Police Department later confirmed officers were investigating the package, but it's unclear whether the third incident is related to the other two packages.

The United States Department of Homeland Security offers safe mail handling procedures on its website regarding suspicious letters or parcels.

How to identify suspicious packages and mail

According to the department’s official training sheet, suspicious packages or mail may include “inappropriate or unusual labeling” such as excessive postage, misspelled words, no return address or an usual return address. Such packages may also not be addressed to a specific person and include “restrictive markings” including the terms “personal,” “confidential” or “do not x-ray.”

Other indicators to keep an eye out for: powdery substances; oily stains or discolorations on the outside; strange odors; excessive tape or string; bulky envelopes or boxes and, of course, any “ticking sounds, protruding wires, or exposed aluminum foil.”

What to do if you encounter suspicious packages and mail

You can find more tips and the full safety flyer at osec.doc.gov.