FRANKFURT AM MAIN, GERMANY - NOVEMBER 11: Kim Kardashian (L) and rapper Kanye West atten the MTV EMA's 2012 at Festhalle Frankfurt on November 11, 2012 in Frankfurt am Main, Germany. (Photo by Jeff Kravitz/FilmMagic)
The scene got so crazy that the Daily Mail said police "struggled" to keep the crowd of mostly teenagers, many of whom had slept overnight in their cars, calm.
Khloe, who jetted in after her Thursday X Factor show to join her sisters, addressed the mob situation in a note on her blog, saying, "We've already had such an amazing response to our signing at Westfield London today and are so excited to see everyone! We can't believe how many incredible fans are waiting outside (several thousand!)
She continued: "In order to keep everyone safe, Westfield had to action a contingency plan for those who stood in line overnight and allowed those people to stay in the carpark. Anyone not already there is of course still welcome to come out today, but I wanted to send a personal message to make sure everyone stays safe!"
The Mail reported that "several women passed out and had to be given medical attention."
Afterward, Kim thanked fans, too, saying on her blog: "The turn out at Westfield was beyond anything any of us had expected. It was a pleasure meeting everyone today!"
Kim's boyfriend, Kanye West, was in London, but not at the shopping center. He and Kim were spotted canoodling on the street on Friday night after dining out. And they surprised fans by popping into a grocery store, apparently in search of snacks.
But it was all a quick trip for the celebs. Kim and Kanye were said to have hopped on a private jet tonight bound for Frankfurt and the MTV European Music Awards, which will be hosted by Heidi Klum on Sunday night.
(Copyright © 2012 USA TODAY)