(CNN)McDonald's has pulled an ad which used the words "Sundae Bloody Sundae" to promote a Halloween dessert, apologizing for "any offense or distress" it may have caused.
McDonald's apologizes for 'Sundae Bloody Sundae' ad
Bloody Sunday is the name for the day in 1972 on which British soldiers shot unarmed protesters in Derry, Northern Ireland, during the Troubles -- resulting in 14 deaths.
The Irish band U2 famously wrote about the horrors of that day in a song called "Sunday Bloody Sunday".
An image of the ad, for a two-for-one dessert offer, was posted on Twitter by an Irish user who spotted it in a McDonald's in Portugal.
After a backlash, McDonald's Portugal took down all promotional material featuring the slogan.
In a statement, McDonald's Portugal said it had developed a "local market activation for a small number of its restaurants in Portugal" -- attempting to celebrate Halloween, not "to upset or insult anyone in any way."
It added: "We sincerely apologize for any offense or distress this may have caused."
In 2013, a London bar apologized after an outcry over a cocktail named "Sun