No poison found after scare at US naval mailroom
The Pentagon said Thursday a suspicious substance in a US naval mailroom near Washington turned out to be harmless, amid jitters in the capital after ricin-laced letters were sent to a senator and President Barack Obama.
"The initial testing of the suspicious substance came out negative for a poisonous material and was cleared" by a hazardous materials team in Arlington, Virginia, the US Navy said in a statement.
Officials had evacuated the naval building in the Washington suburb after a white, powdery substance raised suspicions.
Concerns over security were running high in Washington after a deadly bombing at the Boston marathon this week and after two letters addressed to Obama and Republican Senator Roger Wicker tested positive for ricin.
The FBI on Wednesday arrested a suspect over the mailings.
Authorities said there was no connection between the blasts in Boston that killed three people on Monday and mailings sent to Obama, Wicker and an unidentified Mississippi justice official.
After preliminary tests on the Obama letter showed traces of ricin, further examinations are to be carried out in the next 24 to 48 hours, the FBI said.
The Secret Service said the letter to Obama had been intercepted at a mail screening site on Tuesday, the same day authorities said a letter sent to Wicker also showed traces of ricin.