The government in Beijing is reported to be introducing the controls to deter people from playing for longer than three consecutive hours.

The measures are designed to combat addiction to online role-playing games such as World of Warcraft and Lineage II.

More than 20 million Chinese play games regularly, mainly in net cafes.

Extreme devotion

Games are serious business in China. Last year, Chinese players spent almost US$500m on online games.

The government has been encouraging the growth of online gaming. It is hosting a two-day games conference in September in Beijing in the hope of attracting more foreign investment.

But the phenomenal popularity of online games has fuelled concerns that some people may be losing themselves in the virtual worlds of massive multiplayer online role-playing games (MMORPG).

In one extreme case, a player killed a fellow player who had stolen his virtual sword. The gamer received a suspended death sentence in June.