Many anxious travellers who had learned of tougher checks have been turning up very early for their flights / AP

Philip Baum says long queues of cautious travellers arriving early for flights could tempt attackers

British airline passengers who react to heightened security checks by turning up early at airports could be unwitting victims of a terrorist attack, a leading security expert has warned. Philip Baum, editor of Aviation Security International, said queues like those seen today at Manchester airport present an obvious target for bombers.

“It is not good security to create crowds of people gathering in one place," he said.

“While I am not expecting an imminent attack, experience of suicide bombings – particularly in Israel and the Middle East – shows that it is often people queuing at the checkpoints themselves who are targeted. Whatever solution we create, it must not create a potential target in the process.”

The long queue that built up at Manchester was not because of heightened security; in fact, for most passengers, checks are unchanged. It resulted from many anxious travellers who had learned of tougher checks turning up very early for their flights.

As a result of this self-fulfilling prophecy, there were hundreds of passengers crowding into an area open to anyone, without screening.

Numerous airports have been targets for terrorists, from Rome and Vienna in 1985 to Bourgas in Bulgaria in 2012.