Romelu Lukaku's representatives have demanded an apology from Juventus and called on the Italian authorities to take action after their client suffered "despicable" racist abuse.

Inter forward Lukaku netted a 95th-minute penalty to salvage a 1-1 draw in Tuesday's Coppa Italia semi-final first leg between the two Serie A heavyweights.

However, Lukaku subsequently received a second yellow card after his celebration, which included holding a finger up to his lips in a "shushing" gesture to Juve's fans, resulted in a melee between the teams. Juve winger Juan Cuadrado and Inter goalkeeper Samir Handanovic also saw red.

Lukaku's agency, Roc Nation Sports International, said the 29-year-old had been subject to racist abuse from sections of the home fanbase in Turin.

In a statement shared on Twitter, Roc Nation Sports International president Michael Yormark wrote: "The racist remarks made towards Romelu Lukaku by Juventus fans in Turin were beyond despicable and cannot be accepted.

"Romelu scored a penalty in the game. Before, during and after the penalty, he was subjected to hostile and disgusting racist abuse.

"Romelu celebrated in the same manner he has previously celebrated goals. The referee's response was to award a yellow card to Romelu.

"Romelu deserves an apology from Juventus, and I expect the league to condemn the behaviour of this group of Juventus supporters immediately.

"The Italian authorities must use this opportunity to tackle racism, rather than punish the victim of the abuse. I am certain that the footballing world shares the same sentiment."

Inter coach Simone Inzaghi also came to the forward's defence.

"I see a player who scores, celebrates, and everything happens there. Lukaku's celebration was misunderstood," he said.

"It certainly wasn't a nice sight to see in a well-conducted and fair match until the 94th minute."

On Wednesday, Inter tweeted: "We are brothers and sisters of the world. Since 9 March 1908, this has been our story.

"We want to firmly reiterate that we stand united against racism and all forms of discrimination."