Police investigating an alleged homophobic and racist attack on the actor Jussie Smollett have released CCTV images of "people of interest" who are wanted for questioning.

The star of the TV series Empire was attacked in the early hours of Tuesday morning in the US city of Chicago.

The assault is being characterized as a "possible hate crime", and involved two men yelling out "racial and homophobic slurs" at Smollett, pouring an "unknown chemical substance" on him, and wrapping a rope around his neck, the Chicago Police Department said in a statement.

No arrests have been made for the attack yet.

On Wednesday, Chicago Police Department spokesman Anthony Guglielmi posted two CCTV images to Twitter, showing a pair of figures wearing black.

He wrote on Twitter: "Photos of people of interest who were in area of the alleged assault & battery of Empire cast member.

"While video does not capture an encounter, detectives are taking this development seriously & wish to question individuals as more cameras are being reviewed."

Smollett, who plays Jamal Lyon in Empire, came out as gay during an appearance on the Ellen DeGeneres Show in 2015. 

He is reported to be recovering in hospital after the assault.

There have been many messages of support for the actor on social media, including from Empire's co-creator, Danny Strong who said he was "deeply horrified and saddened" by the attack.

Meanwhile, actress Taraji P. Henson, who plays Smollett's mother on the TV show, shared a clip from one of his music videos on Instagram and wrote: "I wish what happened to my baby was just one big bad joke but it wasn't and we all feel his pain right now.

"@jussiesmollett is pure love to the bone AND THAT IS WHY SO MANY ARE FEELING HIS PAIN BECAUSE IT IS OUR PAIN!!!

"I tell you one thing HATE WILL NOT WIN!!!! My baby is resilient and love still lives in him.

"The devil and his minions are very busy right now but one thing is for sure and two things are for certain #GODIS and that is all I know."

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