Shares in two of China’s biggest online gaming firms have slipped after a state media outlet called them “electronic drugs”, the BBC reports. Tencent and NetEase shares fell more than 10% in early Hong Kong trading before regaining some of those losses. In recent months, Chinese authorities have announced a series of measures to tighten their grip on technology and private education companies. An article published by the state-run Economic Information Daily said many teenagers had become addicted to online gaming and it was having a negative impact on them. The news outlet is affiliated with the official Xinhua news agency. The article cited Tencent’s hugely popular game Honor of Kings, saying students were playing it for up to eight hours a day, and asked for more curbs on the industry. “No industry, no sport, can be allowed to develop in a way that will destroy a generation,” it said before going on to liken online games to “spiritual opium”. A major shift in policy came as authorities try to ease the financial pressures of raising children. Officials have been worried after China’s latest census showed that the birth rate had fallen to the lowest in seven decades.