Authorities investigating cargo flights in N.J., Pa.

Law enforcement officials are investigating reports of suspicious packages on cargo planes in Philadelphia and Newark, N.J.

Transportation Security Administration spokeswoman Kristin Lee says the planes landed safely and are being swept by law enforcement.

The planes have been moved to a remote location so law enforcement officials can investigate.

Philadelphia International Airport spokeswoman Victoria Lupica says Philadelphia police and other agencies are with a plane at a remote part of that airport. Video from the airport shows emergency vehicles around a UPS jet.

A spokeswoman for United Parcel Service Inc. did not immediately know what prompted authorities to search the flight at Philadelphia. The company says it is working closely with authorities. 

A suspicious package in the United Kingdom prompted searches of cargo planes and a truck in the U.S.

During a basic security screening process in the United Kingdom, officials found a suspicious item on a cargo plane, according to a U.S. government official who spoke on condition of anonymity to discuss the ongoing investigation.

U.K. officials discovered that a toner cartridge on the plane had been manipulated and found wires attached to it and white powder.

Tests on the device came back negative for explosives, according to a law enforcement official who also spoke on condition of anonymity to discuss the investigation.

Concerns about the possibility of similar and potentially dangerous devices shipped elsewhere prompted officials to check other cargo planes headed to the United States.