Due to their proximity to the Shenzhen border, towns in the northern parts of Hong Kong, notably Sheung Shui and Yuen Long, have become hubs for parallel traders who have been buying up large quantities of goods, forcing up local prices and disrupting the daily lives of local citizens. Since 2012, there has been an increase in mainland parallel traders arriving in the North District of Hong Kong to re-export infant formula and household products – goods popular with mainlanders – across the border to Shenzhen. The volume of smuggling activity spilled over into Tuen Mun and Sha Tin in 2014.