Kendall and Kylie Jenner and Khloe Kardashian have axed a number of planned public appearances.
The reality TV siblings have decided to call off some upcoming signings in the wake of their sister Kim Kardashian West's recent traumatic ordeal in Paris, where she was held up at gunpoint in her hotel room and robbed of millions worth of jewels.
A source told Access Hollywood: "Due to recent events and ongoing security issues, all signings have been cancelled."
This comes after it was revealed that filming on 'Keeping Up With the Kardashians' has been put "on hold indefinitely".
E! News have confirmed the crew were not filming at the time of the robbery, and have sent their "love and support" to the TV personality following the attack.
A spokesperson from the broadcasting network told Us Weekly: "All of us at E! are incredibly thankful that Kim Kardashian West is safe, and we send her and her family our love and support.
"'Keeping Up With the Kardashians' was not filming at the time of the robbery. Our focus right now is entirely on Kim's well-being."
And Kim - who has three-year-old daughter North and 10-month-old son Saint with her rapper husband Kanye West - has since left New York to fly home via a private jet to California with extra security.
Speaking about the 'Selfish' authors travel methods since her ordeal, a source said: "They had several security guards with them and only had two SUVs to take them to the airport... They are flying private."
Kim reportedly blames herself for the accident, and is worried she attracted the attention of the thieves by posing with her jewels on social media.
An insider previously said: "Kim's in shock and blaming herself. She's tearing herself up that she Snapchatted the ring so much and wore it all the time. This incident is making her question everything. How she dresses, what she does."