Forty people underwent precautionary decontamination last night after a suspicious white powder was mailed to the Midtown diplomatic outposts of three countries.
There were no reported injuries in what officials suspect was an elaborate hoax. The powder tested negative for anthrax or other dangerous substances.
Sources said the letters were delivered to the UN missions of Uzbekistan, Austria and France and bore postmarks from Texas.
All were discovered between 4 p.m. and 6:30 p.m.
The missives sparked a response from the NYPD Emergency Service Unit, the city's Department of Environmental Protection, the FDNY, the FBI and the Health Department, among other agencies.
Each letter was accompanied by a single-sentence note that made reference to al Qaeda but did not make any demands or provide any motive for why the powder was sent.
"The substance is being tested and we'll know more about it tomorrow," said a spokesman for the city's Health Department last night.