The student newspaper of Notre Dame University in Indiana has had to apologise for a cartoon which joked about attacking gays.

The cartoon, published last Wednesday, contained the lines: “What’s the easiest way of turning a fruit into a vegetable?. . . A baseball bat.”

After students and the Gay and Lesbian Alliance Against Defamation expressed anger over the cartoon, the newspaper ran an apology for it.

It read: “There is no excuse that can be given and nothing that can be said to reverse the damage that has already been done by this egregious error in judgment.”

According to GLAAD, the cartoonist had originally used the punchline “AIDS” in the strip, although it has been since been removed from his blog. The gay group said both versions were “abhorrent”.

The three authors of the cartoon apologised, saying they had hoped to address the “ridiculous” mindset of homophobia but accepted their work was offensive.

Today, the assistant managing editor who oversaw publication of that issue resigned.

Kara King wrote that a misunderstanding meant she had not seen the cartoon before it was published but said she was “solely responsible for providing a forum for this message of hate”.