New York City’s buses must display a controversial advertisement that refers to Muslims killing Jews, a judge has ruled.

New York’s Metropolitan Transportation Authority (MTA) had opposed the advertisement, arguing it could incite terrorism and violence.

Judge John Koeltl rejected the argument and said the ad was protected under the US constitution, which enshrines the principle of free speech.

The ad, a parody paid for by the controversial American Freedom Defense Initiative, lead by notorious anti-Muslim blogger Pamela Gellar and author Robert Spencer, depicts a man wearing a scarf around his face, accompanied by this quote: “Killing Jews is Worship that draws us close to Allah.”

The quote adds that his actions are attributed to “Hamas MTV,” and then states: “That’s His Jihad. What’s yours?“, with “Hamas TV” being a reference to Palestinian Media Watch’s translation of a hateful, anti-Israel music video released online.

The ad includes a disclaimer that the ad’s statement does not reflect the MTA’s stance. It’s also not the first time the Authority will run an ad from the AFDI, which touts itself as a pro-Israel organization.

The ad has already been displayed on public transport in Chicago and San Francisco.

Judge John Koeltl said that although he was sensitive to security concerns, the MTA had underestimated the tolerance of New Yorkers and overestimated the potential impact of the ad.

“It strains credulity to believe that New Yorkers would be incited to violence by ads that did not incite residents of Chicago and San Francisco,” he said.

Judge John Koelt delayed enforcing his ruling for 30 days so the MTA could decide whether to appeal.

MTA spokesman Adam Lisberg said they were “disappointed in the ruling and are reviewing our options”.

The American Freedom Defense Initiative is run by controversial blogger and activist Pamela Geller. It is listed as an anti-Muslim group by the Southern Poverty Law Center, a civil rights group.