A Sinn Fein MP has apologised for posting a video showing him with a Kingsmill-branded loaf on his head on the anniversary of the Kingsmill massacre.
Barry McElduff insisted the post was not meant as a reference to the republican murders of 10 Protestant workmen in 1976.
Kingsmill is a well-known brand of bread in Northern Ireland. It shares a name with the south Armagh village that witnessed one of the most notorious incidents of the Troubles, when gunmen stopped a van carrying textile workers on their way home, identified the Protestant occupants, lined them up at the side of the road and shot them.
Only one of the 11 men gunned down survived the attack.
In the video, West Tyrone MP Mr McElduff, who is known for his light-hearted social media contributions, is at one point filmed walking around a shop with a Kingsmill loaf on his head, asking where the store kept the bread.
It was posted on Friday - the 42nd anniversary of the Kingsmill outrage.
Some accused Mr McElduff of making a tasteless reference to the atrocity, with a number of unionist politicians calling for his resignation.
On Saturday, the republican MP deleted the video and posted an apology on Twitter.
"Have deleted video post. Had not realised or imagined for a second any possible link between product brand name and Kingsmill Anniversary," he said.
"Further, I apologise for any hurt or offence caused. Never my intention to offend anyone who has suffered grievously."
Democratic Unionist Assembly member William Irwin had demanded clarification of what he branded a "bizarre" post.
"Was it tomfoolery or a blatant insult to innocent victims?" he said.
"The timing and brand of bread raises many questions about the motivation behind this video.
"Given Sinn Fein's repeated insensitivity to victims and glorification of terrorists, PIRA victims throughout the United Kingdom have interpreted this video as a calculated and deliberate insult."
TUV leader Jim Allister said it stretched the "bounds of credibility well beyond breaking point" to suggest it was not a deliberate reference to the Kingsmill attack.
"Sinn Fein's utter contempt for victims is clearly on display here," he said.
"Any talk of equality or human rights from that party is once again exposed as so much cant and hypocrisy."
Ulster Unionist councillor David Taylor claimed Mr McElduff was unfit to be a public representative.
"Barry McElduff really is beyond contempt and should be truly ashamed of himself for his actions," he said.
Alliance Party leader Naomi Long tweeted Mr McElduff: "I see you have deleted your video. Will you also explain what on earth you were thinking of, posting this on the anniversary of the Kingsmills Massacre?
"Have you any apology to make to those victims & survivors deeply hurt by your antics whether deliberate or not?"