Nick Jonas Evacuates Prague Stage When Laser Pointer Shines on Forehead

Nick Jonas wasn't playing any games during the Jonas Brothers' Prague concert ... evacuating the stage when a red laser hit his face -- sprinting to safety.

The singer-songwriter hit the stage in the Czech Republic Tuesday night ... and, right in the middle of the show, NJ seemed to freak out about something and started running, barreling off the stage toward cover.

Check out the video ... Nick hitting every stride perfectly here, turning a corner and disappearing from sight -- while someone who looks like security runs alongside him.

A photo taken of Nick shows exactly what kicked the star into high gear ... a pulsing red dot on his forehead -- much like one might see in the movies from a rifle scope, right before someone's assassinated.

Clearly, Jonas wasn't taking the chance it was just a prank, deciding to evacuate the stage just in case. The other two Jonas Bros reportedly also then exited the stage.

Event organizers told Variety that the disruption lasted several minutes ... but, the boy band eventually returned to the stage and finished off their set without further incident.

The Jonas Brothers are currently on their "Five Albums, One Night" tour which will end in just a few hours in Krakow, Poland.