Four Dirt Bikers Collide During Argentina Competition in Wild Video

A dirt bike race in Argentina caused quite the calamity ... a stuck bike resulted in multiple collisions during the competition -- though organizers say riders only sustained minor injuries.

Video shows how the crash at Enduro del Invierno in Mar del Plata, Argentina went down ... beginning after one moto rider got himself and his bike stuck in beach sand -- and he frantically waves to keep other racers from plowing into him.

A few bikers just barely miss the competitor ... before one runs right through rider and bike alike.

All hell breaks loose after the first crash ... with a second racer slamming into the mess a moment later, and a third flying through the air and smashing into the pile of motorcycles.

One biker rolls down a small embankment and lies completely still for what feels like ages -- but ultimately all the riders managed to scramble away from the wreckage.

Despite how serious the crash appears on video ... organizers of the weekend event claim the riders only sustained relatively minor injuries -- a broken collarbone and fractured foot being the worst of them. One rider was knocked unconscious, though he's apparently just fine now.

We're not sure those competitors would describe those injuries as "minor." But -- safety first ... always wear a helmet!!!