Knocked Up star Katherine Heigl and Ashton Kutcher are to star together in thriller Five Killers.

The pair will play a married couple who fear their neighbours are assassins out to kill them, Variety reports.

Wonder if it will features scenes with Kutcher posting messages on Twitter about the hired killers next door?

The film sounds like a far cry from the rom-coms that catapulted Heigl to fame following success with TV show Grey's Anatomy (pic). The actress has stressed that she is keen to do her own thing and not be pigeonholed as the next Julia Roberts.

She previously said: "I can't help but feel that is a little insulting to Julia Roberts. There's not another woman who I look at and think, 'That's it, that's whose career I want to have.' I'm just me and trying to do the best I can in every decision in any given moment."

Shooting for Five Killers is scheduled to begin next month in Atlanta and southern France.