Sales of BlackBerry’s (BBRY) new BlackBerry Z10 smartphone are reportedly off to a “strong start” in the United Kingdom, according to checks performed last week by Jefferies & Company. In a note to clients on Friday, analyst Peter Misek reported stock-outs at a number of retailers across the UK. According to Misek, the white version of the BlackBerry Z10 has seen particularly strong early demand. “We believe Carphone Warehouse is seeing widespread sell-outs while O2, Vodafone, Orange and EE are seeing robust demand,” he wrote in a note obtained last week by Forbes. “We estimate sell-in to be at least several hundred thousand units. To put that in perspective, the iPhone had first weekend sales of 5 million+ in the U.S. The U.S. is five times larger so continued strong sales could bode very well for Blackberry.”