In this June 24, 2014, file photo, Homeland Security Secretary Jeh Johnson testifies on Capitol Hill in Washington. Johnson is ordering increased security measures at some overseas airports offering direct flights to the United States. The Homeland Security Department would not immediately say July 2 whether the increased measures were in response to intelligence about a specific threat. But a U.S. counterterrorism official says American intelligence has seen indications that certain terrorist groups in Yemen and Syria are working on a bomb that could make it through airport security undetected. (AP Photo/Charles Dharapak, File)