British singer Leona Lewis was forced to cancel a promotional trip to Germany after being attacked at a book signing in London, her spokesman tells AFP.

“Leona is obviously shocked after yesterday but is OK,” the spokesman says, referring to the incident Wednesday when “a guy came up and punched her to the side of the head.”

The assailant didn’t appear to say anything to Lewis, and the attack appeared unprovoked. Security quickly intervened, and the man was arrested.