A series of anti-Islamic ads that were set to make their debut in New York City's transit system on Monday faced sharp criticism, including an ad featuring recently beheaded American journalist James Foley kneeling beside the masked militant who killed him, being pulled out at the last moment.

The ads, which were supposed to be showcased on MTA buses and in subway stations, were scheduled to begin running on Monday in New York and San Francisco, but the group's leader Pamela Geller decided to hold back after facing criticism from elected officials and Foley's parents, the Associated Press reported.

Paid by the American Freedom Defense Initiative and run by controversial anti-Islam blogger Geller, the announcement that the ad would no longer be showcased was notified to Foley's parents through a letter, Geller's attorney, David Yerushalmi, said, adding that other anti-Islamic ads will go forward.

"As a mother, and one who still feels the pain of the hideous murders of many in her extended family by the Nazis, and with friends in Israel brutally affected by Islamic terrorism as a constant of daily life, Ms. Geller understands and feels intimately the pain your clients are suffering," reads the letter by Yerushalmi.

"For this reason, and this reason alone, [Geller has] reached out as early as this morning to the New York and San Francisco transit authorities' respective advertising agents to pull the displays depicting the captive Mr. Foley prior to his beheading."

Touted to be an "educational campaign," Geller's group spent $100,000 to spread awareness about the dangers of Islam and extremist groups like ISIS and Hamas, which the U.S. government and mainstream media allegedly tend to ignore, New York Daily News reported.

"Our organization has created this campaign in order to educate people about Jihad," Geller told 1010 WINS earlier this month. "I don't think the truth is controversial. I think we're entering a very dangerous period, and I don't think the American people should be disarmed in the information battle space."

However, the campaign was criticized by Foley's parents and critics as being bigoted and slanderous to law-abiding Muslims, CBS News reported.

Public Advocate Letitia James slammed the MTA for green-lighting Geller's ad in the first place. "The MTA's advertising policies make no sense and are woefully inconsistent," said James.

"The MTA said it allowed the ad because courts have ruled that the transit system is a public forum, and that banning viewpoints from being expressed in that forum violates the constitutional right to free speech," CBS News reported, adding that one of Geller's ads, which references "killing Jews," has been rejected in the past.

The public advocate "knows full well that a federal court ruling prevents us from banning the Geller ads," said MTA spokesman Kevin Ortiz.

Last week, the campaign was denounced by a gathering of religious and political leaders of all faiths and backgrounds on the steps of City Hall, the AP reported.

"That has no place here in New York City or anywhere else," City Council Speaker Melissa Mark-Viverito said of the ads.

"How dare these ads suggest and equate the American Muslim community with ISIS?" Rabbi Marc Schneier added.

Meanwhile, the AFDI purchased space next to 228 clocks in 39 subway stations for ads that called enemies of Israel "savages" last year.