Lukaku was subjected to abuse during the first leg at Juventus "before, during, and after the penalty" he scored to earn Inter a 1-1 draw, the player's representatives said.
The police did not specify the length of the bans that fans would face for the offence. They were identified using video footage from the stadium.
Some Inter fans also taunted their Juve rivals during the match, with chants referring to the 1985 Heysel stadium disaster, police added.
The police findings will be passed on to the football authorities for possible further action.
Lukaku will play in the return leg on Wednesday after his one-match ban was overturned by the president of the Italian Football Federation (FIGC).
Lukaku was sent off after receiving a second yellow card for his goal celebration, during which he held his finger up to his mouth to 'shush' Juventus fans.