It's getting pretty heated on the set of AMERICAN IDOL -- but it's not the contestants causing tongues to wag.

BARBARA WALTERS revealed on her TV talk show THE VIEW, that following reports new judge NICKI MINAJ cursed out CAREY on the set, threatening "If I had a gun, I'd shoot a b****," CAREY disclosed she had hired extra security.

YAHOO.COM reports, "CAREY is very concerned and not 'comfortable emotionally.' WALTERS said she doesn't actually think anything will happen but can't take a chance. 'NICKI said after the meeting, 'I love you but we may fight again.' MARIAH said, 'No I will not.'"

The other new judge, KEITH URBAN, just wants everything to be normal, notes YAHOO.

Wooooooow is all I can say. Nicki is one crazy b****!!!