FIFA's Infantino shows support for Umtiti, Banda after racist abuse
Italian newspaper Gazzetta dello Sport reported the match was paused for several minutes while an announcement was made in the stadium calling for the chants to be stopped.
Home fans chanted Umtiti's name to drown out the abuse and Lecce President Saverio Sticchi Damiani said the French World Cup winner, who is on loan from Barcelona, had asked for the game to resume.
Lecce came from behind to win the Serie A game 2-1, with Frenchman Umtiti leaving the pitch in tears.
"Racist insults were drowned out by choruses of encouragement towards our champion," Lecce said in a statement.
Umtiti posted a message on Instagram saying: "Only football, fun, joy. The rest doesn't count."
Infantino showed his support for Umtiti and Zambian Banda in a social media post.
"Solidarity with Samuel Umtiti and Lameck Banda - let's shout it loud and clear: No to racism," he wrote as a caption to photos of Umtiti and Banda.
"May the huge majority of fans, who are good people, stand up to shut up all the racists once and for all."
Lazio said in a statement on Thursday: "During the Lecce-Lazio match, the referee was forced to interrupt the game due to racist chants towards a player of the home team.
"Lazio once again condemns the perpetrators of this despicable, shameful and anachronistic gesture and will, as always, offer its utmost cooperation to the authorities in identifying those responsible.
"Lazio fans are not racists and cannot be associated with a few individuals who seriously damage the club's image."
Umtiti's parent club Barcelona also issued a statement of support for the French defender on Thursday, saying it "stands firm in its total opposition to any and all forms of violence, racism, xenophobia, and intolerance."
A section of Lazio fans were previously punished by European soccer's governing body UEFA for fascist salutes and racist chants, including after a Europa League game against French side Rennes in October 2019.