PHILADELPHIA (AP) — Philadelphia Mayor Jim Kenney warned residents he will end the city's annual Mummers Parade if organizers don't curtail participants' inappropriate behavior, including blackface.

The mayor sent a letter to the organizers of the four Mummers divisions and requested they meet with officials following another blackface controversy at this year's event, Kenney spokesperson Lauren Cox said Thursday.

“The future of the parade is in jeopardy if Mummers leadership does not make immediate changes to better control the parade,” Kenney wrote in the letters.

The New Year's Day parade has a long history of racially and socially offensive displays. The parade features ornate costumes and musical performances and attracts thousands of spectators each year. City staffers monitoring the parade route this year saw at least one marcher wearing blackface, officials said. When they reported it, parade officials disqualified the group from competition.

The mayor criticized two men at this year's parade for wearing blackface, calling their actions “abhorrent and unacceptable.”

“This selfish, hateful behavior has no place in the Mummers, or the city itself. We must be better than this," the mayor tweeted shortly after this year's event.

The men, Kevin Kinkel and Mike Tomaszewski, defended their decision and said it wasn’t racist. They said the group was paying homage to Gritty, the hairy, googly-eyed mascot of the Philadelphia Flyers that is orange all over, face included.

Many of the brigade’s marchers wore variations of face paint in the Flyers’ colors of black, orange and white. But the two men cited appeared to have just blackface.

Kenney asked the parade's organizers to put mechanisms in place for accountability if participants violate Mummers' rules next year.