A US defense official confirmed that 2 pieces of mail delivered to the Pentagon tested positive for ricin, a poison extracted from castor beans.
One of the envelopes was addressed to Secretary of Defense James Mattis and the other envelope was addressed to Chief of Naval Operations, Admiral John Richardson, CNN reported.
All US Postal Service mail received at the Pentagon mail screening facility on Monday's currently under quarantine and poses no threat to Pentagon personnel, according to Pentagon spokesperson Col. Rob Manning.
"On Monday, the Pentagon Force Protection Agency detected a suspicious substance during mail screening at the Pentagon’s remote screening facility," Manning said in a statement.
"The envelopes were taken by the FBI this morning for further analysis," Manning added.
The FBI issued a statement saying it has taken possession of 2 suspicious envelopes screened at the Pentagon mail facility and they're undergoing more testing.
"On Tuesday, October, 2, 2018, in coordination with the Pentagon Force Protection Agency, FBI Special Agents took possession of 2 suspicious envelopes that had been screened at the Pentagon mail facility. Those envelopes are currently undergoing further testing. As this is ongoing, we'll have no further comment."
On the other side of the country, 2 people were hospitalized Tuesday when an envelope containing white powder was sent to Ted Cruz’s Houston campaign headquarters.
There's no reports indicating the 2 incidents are related.