Mark Davis/WireImage 1 / 15
Mark Davis/WireImage 1 / 15

Teen superstar Miley Cyrus has explained her outburst aimed at a fan during her vacation in Costa Rica, insisting she "can't tolerate that kind of rudeness".

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The singer-actress was enjoying a break with her Australian boyfriend, Liam Hemsworth, when the couple were stopped by a group of fans eager for autographs and photos.

Cyrus posed with the youngsters, but as they went to leave, one fan muttered, "A--hole!"

The 19-year-old star then rounded on the individual, declaring, "What the f---? Are you for real?"

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In a series of posts on Twitter, she writes, "Been trying not to tweet & just enjoy the holidays but just to clear something up I would never swear to a fan. When someone yells something so rude making me look like an 'a**hole' in front of fans who I am more than happy 2 take a picture w/ (with) I can't tolerate that kind of rudeness. Every1 who was there apologized 4 the woman's brusque behavior. She obviously wasn't a fan. Hope every1 has a Merry Christmas!"

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