Kourtney Kardashian has hit out at the person who threw a flour bomb at her sister Kim last night (22.03.12).

The 31-year-old star was on the red carpet at The London Hotel in West Hollywood when the incident happened, and pregnant sister Kourtney has suggested they would not have done the same to her.

She wrote on twitter: ''Classy to flour bomb my sister at her charity event helping women. I wonder if they would have dared thrown the flour at my hormonal and pregnant self! (sic)''

Despite Kourtney's claims it was a ''charity event'', their mother Kris Jenner - who was also at the event - revealed it was actually to promote her new fragrance.

Before the flour bombing, she wrote: ''So excited for @KimKardashian True Reflection fragrance launch tonite!! Congrats Kimmy I'm so proud of you!! AND you smell amazing LOL!!! (sic)''

Kim was ushered into a room where she removed her flour covered jacket and the assailant - a woman - was arrested.

Speaking afterwards, Kim said: ''That probably is the craziest, unexpected, weird thing that ever happened to me.

''Like I said to my make-up artist, I wanted more powder and that's a whole lot of translucent powder right there!''