American intelligence officials have been concerned about new al-Qaida efforts to produce a bomb that could go undetected through airport security. There is no indication that such a bomb has been created or that there's a specific threat to the U.S.
TSA does not conduct screening abroad, but has the ability to set screening criteria and processes for flights flying to the U.S. from abroad, according to a Department of Homeland Security official, who spoke on condition of anonymity.
During an interview aired Sunday on NBC'S "Meet The Press," Homeland Security Secretary Jeh Johnson declined to speculate on whether new security procedures called for overseas will be required at domestic airports in the future.
TSA will not disclose which airports will be conducting the additional screening, although it will be at some airports with direct flights to the U.S. Industry data show that more than 250 foreign airports offer nonstop service to the U.S.
Aviation remains an attractive target to global terrorists, who are consistently looking for ways to circumvent aviation security measures, the DHS official said. Some details on specific enhancements and locations are sensitive because U.S. officials do not want to give information "to those who would do us harm," the official said.
American intelligence officials said earlier this week that they have picked up indications that bomb makers from Yemen-based al-Qaida in the Arabian Peninsula have traveled to Syria to link up with the al-Qaida affiliate there.
Al-Qaida in the Arabian Peninsula long has been fixated on bringing down airplanes with hidden explosives.
It was behind failed and thwarted plots involving suicide bombers with explosives designed to be hidden inside underwear and explosives secreted inside printer cartridges shipped on cargo planes.