updated 10/04/2012 AT 6:00 PM ET
•originally published 10/05/2012 AT 12:00 PM ET
It’s the feud of the season!
In the space of just a few weeks, American Idol judges Mariah Carey and Nicki Minaj have become locked in a battle complete with f-bombs, a reported gun threat – and a bemused Keith Urban caught in the middle.
The once cordial stars are now seemingly deadlocked at the judges’ table. So where did all the fighting begin?
Minaj’s profanity-laced outburst (which was caught on video and posted on TMZ) may have been the final straw in a series of difficulties between the stars.
“Mariah has been saying little things to jab at Nicki from day one of shooting,” an Idol source tells PEOPLE. “Mariah doesn’t think Nicki can sing and doesn’t think she should be judging folks. Nicki has been taking all of the jabs, but on this particular day she lost it.”
Other insiders insist Carey did not provoke Minaj. But clearly tensions were high, as Minaj had stormed off the set earlier in the day.
“There was a contestant who liked opera, and Mariah was talking to her as a pop singer who also liked opera,” says one insider. “Nicki cut her off and slammed her fist on the table. Mariah may have been going on a bit too long but she did apologize. But then Nicki flipped out and started yelling.”