Ten more letters containing suspicious but harmless white powder were sent to schools yesterday in the US capital, the FBI said, after dozens of similar letters prompted school evacuations the previous day.
A total of 39 letters to 34 Washington schools have now been recovered for analysis, said the Federal Bureau of Investigation, which announced it has launched an investigation into who mailed the packages.
Of the 10 letters found yesterday, six reached schools and “four more letters were intercepted by postal inspectors,” Andrew Ames of the FBI’s Washington field office said.
“They were deemed not hazardous, but they were sent to the lab for further testing,” he said.
The FBI released a list of schools which received the suspicious letters on Thursday; the private school attended by President Barack Obama’s daughters was not on the list.
In a statement, the FBI said the potential threat over a two-day period sent federal authorities scrambling, “causing some school evacuations and tying up hundreds of hours of police and law enforcement resources” as hazardous materials teams responded to each school that received letters.
“To date, no hazardous substances were found in the mailings. No illnesses or in-juries have been reported as a result.”
The FBI said the letters were all likely mailed from Dallas, Texas, “and are similar in style and content to other suspicious letters under investigation by Dallas FBI and US postal inspectors,” but the agency refused to discuss the letters’ contents.
Fox 5 television station said the letters referenced the extremist group Al-Qaeda but did not contain a specific threat.
The recent killing of Al-Qaeda leader Osama bin Laden in Pakistan at the hands of US commandos has prompted authorities to urge caution for possible retaliatory strikes on US soil.
Use of white powder sent through the mail, meanwhile, recalls the deadly 2001 anthrax mailings in Washington, which killed five people and injured 17, rattling the US public days after the September 11 terror attacks that year.
In that case, a federal investigation concluded scientist Bruce Ivins, who killed himself in 2008, was to blame for the mailings.