(CNN) — Two pieces of mail delivered to the Pentagon mail facility on Monday have initially tested positive for ricin, according to a US defense official.
The mail facility is in a separate building on the grounds of the Pentagon and the piece of mail which tested positive never entered the Pentagon building. All mail delivered to the Pentagon Monday was put into quarantine, according to the official.
The FBI and the Pentagon Force Protection agency are responding and further testing is expected to be done by the FBI, the officials said.
Ricin is a highly toxic compound that is extracted from castor beans and has been used in terror plots. It can be used in powder, pellet, mist or acid form.
This story is breaking and will be updated.