Chief Keef -- Caught Up in Chicago Shooting ... Instagrammed AK-47 Photos

Chief Keef somehow got mixed up in a shooting early Wednesday AM that put someone in the hospital, TMZ has learned.

We called Keef's people to determine the extent of the rapper's involvement -- his lawyer tells us Keef wasn't the shooter ... he just happened to be present when shots were fired.

The Northfield PD says the shooting victim is in ICU.

The rapper really knows how to implicate himself in a crime -- on Monday, Keef plastered his Instagram page with photos of guns, including an AK-47, and the photos appear to serve as a warning. Keef wrote the captions, "Another situation. Already."

And voila ... another situation already.