Sean Kingston Allegedly Beaten By Migos ... Shot Fired

Sean Kingston was beaten up badly Tuesday and people on scene say Migos was the culprit ... but the story is bizarre and the group is not wanted by cops, at least not yet.

Law enforcement sources tell us it went down late afternoon at the Sands Expo and Convention Center in Vegas. We're told Kingston and the guys from Migos got into it over an argument involving Soulja Boy and the 3 members of Migos beat Sean badly, allegedly kicking him and stomping on his head.

Law enforcement tells us someone from Sean's camp pulled out a gun and fired once, but didn't hit anyone. That person was detained by security and turned over to the Vegas PD.

By the time cops arrived both Sean and Migos had left. A short time later Sean was pulled over for a traffic stop and became "semi-cooperative," though he did not name names.

We're told police want to speak with Migos, but they are quick to add members of the group are not "wanted" by cops.