Maryland State Police received an anonymous call threatening commercial flights, claiming bombs and chemical weapons were on board.
According to the Federal Bureau of Investigation, the threats of chemical weapons inside these international flights were considered not credible. However, investigations were being carried out as precautionary measure, reports said.
According to multiple media reports, a male caller made threats against at least 10 flights in a quick series of calls to local police around the country.
Yesterday, two American military jets flew alongside Air France flight to New York as a precautionary measure.
Threats were also sent to Delta Airlines Flight 69 from London's Heathrow to Newark, and United Airlines Flight 37 from Edinburgh Airport in Scotland to Newark. Both the flights were cleared of any chemical weapon.
"No incidents or hazards reported on board the flight by either the passengers or its crew," the FBI told news outlets.