An incoming city councilwoman set off a firestorm Wednesday with a Facebook post that blamed some “knockout game” attacks on tensions between blacks and Jews.

Councilwoman-elect Laurie Cumbo, who will represent Crown Heights when she takes office next month, said many black constituents told her they feel threatened by “Jewish landlords” trying to move them out of the community.

Cumbo said “resentment” over the perceived push could “offer possible insight as to how young African-American/Caribbean teens could conceivably commit a ‘hate crime’ against a community that they know very little about.”

Cumbo’s observations were included in a 1,200-word epistle to her supporters. In it, she denounced the attacks and called for strong punishment.

But several Jewish leaders, including Assemblyman Dov ­Hikind, said the comments were off base and did more harm than good.

“Some of your comments were downright counterproductive,” Hikind said in a letter to Cumbo posted on his blog.

Hikind said Cumbo’s assessment “almost rings as an apology for those who are committing violent crimes as a response to their resentment.”

Crown Heights was shattered by 1991 riots sparked by tensions between blacks and Jews.

Cumbo could not be reached for comment.

Rabbi Marc Schneier, president of the Foundation for ­Ethnic Understanding, said Cumbo’s comments were “groundless and baseless.”

“We need to take a step back and choose our words carefully,” he said.