Mariah Carey has reportedly beefed up her security after Nicki Minaj threatened to shoot her.

The 'American Idol' judge and the 'Super Bass' hitmaker were involved in a heated argument on the set of the talent show on Tuesday (02.10.12) and as a result the 42-year-old singer has hired extra safety personnel to protect her.

Mariah contacted chat show host Barbara Walters, who read out a statement on 'The View' which revealed several staff members had heard Nicki say: ''If I had a gun I would shoot the b***h.''

Barbara related: ''She said she is very concerned, she's with her twins, she doesn't feel that anything would happen, but Nicki is unpredictable and Mariah says she can't take a chance and has hired extra security.

''Nicki has not apologised, but they were together in meetings ... during which Nicki said, 'I love you, but we might fight again!'

''Mariah said at this point she doesn't feel comfortable emotionally but she will continue with the show because she loves mentoring the contestants.''

Following the pair's dispute, Nicki took to her twitter account to post a series of furious tweets.

She wrote: ''Tried to keep quiet but let's go!!!!

''I thought we resolved it yesterday but I see u want ur pity party to continue. So I'm bout to po dot tea. (sic)

''I don't call tmz n Barbara Walters cuz I stand on my own two feet. Never needed an army. God is good. Insecurity is as cruel as the grave. (sic)

''I guess it hurts 2 have the producers tell u to ur face that nicki is the best judge we've had since simon. Awww, poor u. Keep them lies cmn. (sic)''