Marketers responsible for promoting the "Sleepy Hollow" season one DVD made a public apology after releasing the "National Headless Day" promo last Tuesday.

The publicity stint kicked off on the same day that Islamic State terrorists released a footage that showed the beheading of American journalist Steven Sotloff.

Like Us on Facebook

The advertising slip-up resulted to criticisms on social media sites, including Twitter.

Think Jam, the marketing firm responsible for the PR stint, issued a formal acknowledgement for their fault. "We apologize for the unfortunate timing of our Sleepy Hollow Headless Day announcement," the firm said in their released statement.

The Fox TV series, which incorporates elements of Washington Irving's "The Legend of Sleepy Hollow" in 1820, presents the legend of a headless horseman.

According to the network, their "National Headless Day" press released was emailed and made public merely minutes before the troubling video of Sotloff's execution was released. Fox's promotion encouraged fans of "Sleepy Hollow" to gather and share eCards in celebration of "National Headless Day."

 "The tragic news of Steven Sotloff's death hit the Web as the email was being sent," Think Jam's statement read. "Our deepest sympathies are with him and his family, and we don't take the news lightly. Had we have known this information prior, we would have never released the alert and realize it's in poor taste."

An apology was also issued by Twentieth Century Fox Home Entertainment. "We regret the unfortunate timing of our announcement and our deepest sympathies go out to the families of all involved," Fox said in its public statement.

The footage of Sotloff's beheading came two weeks after the Islamic State of Iraq and Syria posted a video on YouTube showing Foley's decapitation.

The PR stint blunder brought on criticisms on Twitter and contributed to the trending hashtag "#headlessday."

"That campaign should've been nixed weeks ago after the first IS assassination," Kevin Cassedy, Twitter user, had written. Other marketers, such as Dave Wong, pitched in with his tweet: "Marketing gone tragically wrong."

TagsSleepy Hollow, National Headless Day, Think Jam, ISIS, FOX Entertainment