3D principal photography has got underway in Moscow on New Regency and Summit Entertainment’s The Darkest Hour after thick smoke from peat bog and forest fires delayed the shoot.

The story follows five people stranded in Moscow in the wake of an alien attack. Summit Entertainment will release theatrically in North America on August 5, 2011 and Fox International is distributing overseas.

The project is the first American 3D production to film in Russia and will shoot in and around Moscow during autumn. Tom Jacobson and Timur Bekmambetov are producers on the project.

Chris Gorak is directing from a screenplay by Jon Spaihts based on the script by Leslie Bohem and MT Ahern. Emile Hirsch, Olivia Thirlby, Max Minghella, Rachael Taylor and Swedish actor Joel Kinnaman star.

Gosha Kutsenko, Dato Bakhtadze, Nikolai Efremov, Arthur Smoljaninov, Georgiy Gromov and Veronika Ozerova comprise the key Russian cast.