Actor Orlando Bloom said his latest film about a fictional biological attack threatening London "could absolutely happen" in the real world and that the increasingly topical subject of terrorism is handled sensitively.

"Unlocked," out in UK theatres on May 5, sees Bloom play a secret MI5 agent who double crosses a CIA interrogator as she races to stop a biological attack on London after accidentally providing terrorists with information.

"The world we live in today, this kind of situation could absolutely happen," Bloom told Reuters at the film's premiere on Tuesday.

"I think our director Michael Apted did a fantastic job, you know, of really handling that with a great deal of care and sensitivity," he added.

Apted, who directed 1999's James Bond film "The World is Not Enough" said the story of "Unlocked" is "getting more and more powerful."

"I don't think you can play games with it. I don't think you can flirt with it or not take it seriously and it's getting more and more frightening as the days and the months go on," he said.