"Empire" star Jussie Smollett was brutally attacked by 2 men who beat him up, put his head in a noose and screamed, "This is MAGA country."

Sources directly connected to Jussie tell TMZ, the actor arrived in Chicago from New York late Monday, and at around 2 AM he was hungry and went to a Subway. We're told when he walked out, someone yelled, "Aren't you that f***ot 'Empire' n*****?"

The 2 men -- both white and wearing ski masks -- viciously attacked Jussie as he fought back, but they beat him badly and fractured a rib. They put a rope around his neck, poured bleach on him and as they left they yelled, "This is MAGA country."

Jussie was taken to Northwestern Memorial where he was treated. He was discharged later Tuesday morning.

ThatGrapeJuice.Net first posted this letter which was sent to Fox Studios in Chicago with cut out letters spelling, "You will die black f**." Our sources say the letter was sent 8 days ago.

Law enforcement sources tell us Chicago PD is investigating the incident as a battery and the police tell us they are treating the incident as a possible hate crime.