A Newsday spokeswoman says the paper received a package labeled anthrax similar to others that have been sent to news organizations across the country.
Deirdre Parish-Williams says mailroom staff and security personnel were aware of the other mailings and quickly spotted the package Friday morning.
The building was briefly closed while police investigated but as of early afternoon, business was back to normal at the offices of Long Island's only daily newspaper.
A 66-year-old California man was arrested Wednesday on suspicion of sending scores of letters containing packets of sugar labeled "anthrax sample," the FBI said. None of the packets has so far tested positive for hazardous material.
Suffolk police said they were sending the substance to a lab for testing.