With more parents buying handsets for their children, mobile phone thieves are starting to target pupils as young as 11, police said yesterday. The robberies are carried out by gangs of teenagers belonging to syndicates feeding the second-hand phone market, said Superintendent Chan Wing-ning, assistant Shamshuipo district commander. 'The gang might say a friend has been assaulted by the victim and demand his mobile phone in compensation,' he said. 'Mobile phones can be stolen when owners put them down while playing in games centres, or they can have their mobile phones snatched while walking in public areas.' Superintendent Cheung Kwai-yee of Kowloon West said some stolen phones were sold to unlicensed traders at second-hand telephone markets in Shamshuipo and Mongkok. But he did not rule out the possibility that some could be smuggled into China. Traders in the SAR usually buy phones at a third of their original price and resell them. Officers arrested 15 unlicensed traders, including a mainland visitor, and seized 177 mobile phones in Mongkok and Shamshuipo during a two-day operation that ended yesterday. Twelve men and three women were freed on bail. Police are checking whether the seized phones were stolen.