The reality TV star and her two siblings, Khloe and Kourtney, attended a public appearance and signing at the Westfield mall in west London on Saturday (10Nov12) and security teams there were overwhelmed when thousands of devotees turned out.
Fans even camped out overnight in a bid to get close to the girls.
A number of youngsters were caught in the crush as the crowd surged to gain a glimpse of the socialites, and three teenagers had to be treated by paramedics after fainting, according to the London Ambulance Service.
Khloe Kardashian even sent out a warning message via Twitter.com, urging supporters to stay safe during the day.
She wrote, "We can't believe how many incredible fans are waiting outside (several thousand!) 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 car park... I wanted to send a personal message to make sure everyone stays safe!"
A spokesperson for the Westfield centre insisted there were no serious injuries in the crowd crush, telling British newspaper The Sun, "The event was very safe, with security and Metropolitan Police managing the crowds with no major injuries."