(AP/Gray News) - Officials are investigating a package that set off an alert at a Facebook mailing facility in Menlo Park, Calif., on Monday.
Mail and packages are run through a screening machine that detects potentially dangerous materials at the facility. The machine alerted workers to a package that possibly contained sarin gas.
Hazardous material firefighters responded to the facility, which was evacuated.
Menlo Park Fire Marshal Jon Johnston said Monday that that there are no reports of injuries.
"Right now we don't have anybody that has any symptoms," he said. "We're just doing verification."
Facebook spokesman Anthony Harrison said four buildings were evacuated and that three have been cleared for people to come back in. The suspicious package was delivered around 11 a.m. to one of the company's mail rooms, he said.
"Authorities have not yet identified the substance found," Harrison wrote.
Sarin is a toxic nerve agent developed by Germany in 1938. Exposure to large doses can result in loss of consciousness, convulsions, paralysis and respiratory failure, possibly leading to death, according to the Centers for Disease Control and Prevention.
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