Oxford University has apologized after a female cleaner was asked to remove "Happy International Women's Day" graffiti from the steps of its Clarendon Building.The offending moment was caught on camera by Oxford Professor, Sophie Smith, who shared the image on Twitter. The photograph shows a woman mopping away the celebratory words, while a group of male security officers stand above her. She captioned the picture, "Oxford security makes a woman cleaner scrub out 맥스카지노�Happy International Women맥스카지노�s Day맥스카지노� on the Clarendon steps. What an image for #IWD, @UniofOxford. #strikeforUSS #UCUstrike"The post was retweeted 13,000 times and received 17,000 likes, with numerous others expressing their annoyance. The hallowed institution swiftly apologized on Twitter, saying "this should not have happened".Smith responded saying that the university should offer a "heartfelt apology" to the woman who was forced to clean the graffiti.For celebrations of International Women's Day from across the world, check out the video above.