Madonna has been criticised for defacing images of Martin Luther King, Jr. and Nelson Mandela.

The 'Unapologetic Bitch' hitmaker - who rush-released tracks from her thirteenth studio album in December after they leaked online - attempted to clarify her reasoning for posting the images, assuring the public she is simply "admiring" the stars by including them in the series of photos.

Writing on her official Facebook page, she said: "I'm sorry. I'm not comparing my self to anyone. I'm admiring and acknowledging there Rebel Hearts. This is niether a crime or an insult or racist! I also did it with Michael jaclson and frida khalo and marilyn monroe. Am I saying I am them. NO. I'm saying they are Rebel Hearts too. And, I didn't do it. My fans did. And I just re posted those photos. My fans aren't racist either. (sic)"

In a separate post on her Instagram page, the star - who is the mother of Lourdes, 18, Rocco, 14, David, nine and Mercy, eight - thanked her fans for editing the images as it is a way of celebrating people who have made a difference to the world.

She wrote: "I would like to thank all my fans for recreating my album cover with the Rebel Heart ribbon on the faces of so many Great Hero's. It shows that you are also celebrating and in admiration of these great freedom fighters!

"I hope to one day accomplish. 1 100th of what these Rebel Hearts have accomplished. As I Said in a previous post "I walk in the footsteps of Giants" and i will continue to do so G*D willing. They are my guiding light. (sic)"

Since making the comments on her social media accounts, she has angered users once again by posting an edited image of Diana, Princess of Wales - who died in a car accident in 1997 - writing, "Yes Princess Diana was. #rebelheart! Anyone who fights for freedom is a #rebelheart (sic)."