A Long Island courthouse was evacuated late Monday after a letter was opened inside the building containing "possibly hazardous material," according to a law enforcement source and someone inside at the time.
The Nassau County Courthouse on Old Country Road in Mineola was cleared around 4:30 p.m. as a precaution after the letter was opened.
Around half a dozen people were reportedly being monitored after coming into contact with the letter.
There was no immediate confirmation on what material may have been inside the letter, nor how it got to the courthouse and who opened it.
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A source later told NBC New York that any claims of there being a hazardous material present may have been unfounded.
The investigation is ongoing.
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