This past weekend, we brought you some set photos featuring the prep work being done in Cleveland for the Avengers production. Well, they actually started filming and we’ve got some videos and photos from the set. No principle actors are visible in the video (which documents a crazy explosion), but Chris Evans is captured in a couple of snapshots. Naturally, if you’re steering clear of any and all spoilers it’s probably best not to click through. On the other hand, if you’re so inclined, hit the jump to see the videos and photos.Directed by Joss Whedon, the film stars Robert Downey Jr., Chris Hemsworth, Chris Evans, Mark Ruffalo, Scarlett Johanssen and Samuel L. Jackson. The Avengers opens in 3D on May 4, 2012.Here are the videos (courtesy of our fearless leader Steve Weintraub, who made the find), showing a major explosion:Here are a couple of photos (via Marvel Movies fan Facebook page and CelebBuzz):the-avengers-teaser-posterHere’s The Avengers production announcement which features the relevant cast/plot info:

Robert Downey, Jr. (“Iron Man,” “Iron Man 2″) returns as the iconic Tony Stark/Iron Man along with Chris Hemsworth (“Thor”) as Thor, Chris Evans (“Captain America: The First Avenger”) as Captain America, Jeremy Renner (“Thor,” “The Hurt Locker”) as Hawkeye, Mark Ruffalo (“The Kids Are Alright”) as Hulk, Scarlett Johansson (“Iron Man 2″) as Black Widow, Clark Gregg (“Iron Man,” “Thor”) as Agent Phil Coulson, and Samuel L. Jackson (“Iron Man,” “Iron Man 2″) as Nick Fury.  Set for release in the US on May 4, 2012, “Marvel’s The Avengers” is the first feature to be fully owned, marketed and distributed by Disney, which acquired Marvel in 2009.

Continuing the epic big-screen adventures started in “Iron Man,” “The Incredible Hulk,” “Iron Man 2,” “Thor,” and “Captain America: The First Avenger,” “Marvel’s The Avengers” is the super hero team up of a lifetime. When an unexpected enemy emerges that threatens global safety and security, Nick Fury, director of the international peacekeeping agency known as S.H.I.E.L.D., finds himself in need of a team to pull the world back from the brink of disaster.

Based on the ever-popular Marvel comic book series, first published in 1963, “Marvel’s The Avengers” brings together the mightiest super hero characters as they all assemble together on screen for the first time. The star studded cast of super heroes will be joined by Cobie Smulders (“How I Met Your Mother) as Agent Maria Hill of S.H.I.E.L.D., as well as Tom Hiddleston (“Wallander”) and Stellan Skarsgård (“Angels & Demons,” “Mamma Mia!”) who will both reprise their respective roles as Loki and Professor Erik Selvig from the upcoming Marvel Studios’ feature “Thor.”