Warner Bros Studios Leavesden has remained tight-lipped about a production set to involve “smoke, flame effects, and bangs” over the next few nights.

The Warner Drive-based company notified residents last Friday (March 24) of the filming out on the back lot between March 27 to March 31.

The letter said: “These dates will involve high level film lighting, use of controlled SFX (special effects), atmospheric smoke, flame effects, bangs, and general production filming noise.”

It added that Three Rivers District Council and all relevant authorities have been notified.

The Watford Observer contacted the studios to ask for more information on what is being filmed.

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However, a spokesperson said that because it is a closed filming facility it is unable to disclose which projects are taking place on site.

Watford Observer: The residents notificationThe residents notification (Image: Newsquest/Warner Bros. Studios Leavesden)

Mysterious filming has also recently been taking place on location nearby, in Kings Langley.

SP Film Productions told locals that a shoot “organized at short notice” was taking place on March 22 for the upcoming movie "Spiral" in Fred and Ginger Coffee, in the High Street.

Whether Spiral is a code name or not is unclear and the studio would not confirm whether the movie is part of a franchise or who is set to star.