(RNN) - Suspicious devices found on two planes in London and Dubai set off a worldwide security scare Friday as three cargo planes were searched on the ground at two U.S. airports.
Both the London and the Dubai flights originated in Yemen.
Authorities searched a UPS cargo plane at Newark Liberty International Airport in Newark, NJ. Two planes at Philadelphia International Airport in Philadelphia, PA were also investigated.
White House Press Secretary Robert Gibbs said President Obama was notified of the potential threat at about 10:30 p.m. Thursday by the Department of Homeland Security.
"The President directed U.S. intelligence and law enforcement agencies, and the Department of Homeland Security, to take steps to ensure the safety and security of the American people, and to determine whether these threats are a part of any additional terrorist plotting," Gibbs said. "The President has received regular updates from his national security team since he was alerted to the threat."
Officials have said the suspicious device found in the plane at East Midlands Airport in the United Kingdom was a "manipulated" toner cartridge that resembled an explosive. The plane was bound for Chicago, IL.
It is unclear whether any explosive devices were found aboard the planes in Newark and Philadelphia, but both planes were swept.
"Out of an abundance of caution the planes were moved to a remote location where they are being met by law enforcement officials and swept," said UPS spokeswoman Jackie Blair in a statement.
The Department of Homeland Security announced "enhanced" security steps for passengers traveling by air, including heightened cargo screening and additional security at airports.
Those measures could include pat-downs, explosive detection devices, advanced imaging technology, and canine teams.
"Some of these security measures will be visible while others will not," the press statement said.
Earlier in the day, suspicious activity was also reported in New York and Maine.
Law enforcement officials in Brooklyn, NY at New York State's Metro Tech Business Center investigated a suspicious UPS truck near a bridge. The New York Police Department said no explosive devices were found.
In Portland, ME, a suspicious package was reported at a federal courthouse. The item turned out to be a backpack that had been placed at the entrance of the courthouse, said John Clark, chief deputy with the U.S. Marshall Service in Portland.
Clark said there is no indication the backpack is related to any of the other packages found on the planes, but that it was being investigated with an "abundance of caution" by the Portland Police office.