(DOD photo by Air Force Tech. Sgt. Brigitte N. Brantley)

Two letters sent to the Pentagon, including one addressed to Secretary of Defense Jim Mattis, have tested positive for ricin, a defense official told VOA on Oct. 2, 2018.

The envelopes containing a suspicious substance were taken by the FBI on Oct. 2, 2018, for further testing, according to Pentagon spokesman Army Colonel Rob Manning.


The two letters arrived at an off-site Pentagon mail distribution center on Oct. 1, 2018. One was addressed to Mattis, the other was addressed to Chief of Naval Operations, Admiral John Richardson, an official told VOA on condition of anonymity.

The Pentagon, headquarters of the US Department of Defense.

The Pentagon Force Protection Agency detected the substance during mail screening, so the letters never entered the Pentagon building, officials said.

"All USPS (United States Postal Service) mail received at the Pentagon mail screening facility [Oct. 1, 2018] is currently under quarantine and poses no threat to Pentagon personnel," according to Manning.

Ricin is a highly toxic poison found in castor beans.

This article originally appeared on Voice of America. Follow @VOANews on Twitter.