Airport security is being increased at UK airports after the United States called for heightened precautions amid reports two terror networks are working together on a bomb that could evade existing measures.
The Department for Transport said the extra measures – which have not been disclosed – were not expected to cause "significant disruption" to passengers and noted that the official UK threat status remained unchanged.
Changes were announced after Washington Homeland Security Secretary Jeh Johnson ordered beefed up security at foreign airports from where aircraft fly directly to the US.
US officials were reported to have said the move was the result of intelligence that groups in Yemen and Syria had joined forces to plot an attack.
"We have taken the decision to step up some of our aviation security measures. For obvious reasons we will not be commenting in detail on those changes," a Department for Transport spokesman said. "The majority of passengers should not experience significant disruption."