China is extending rules requiring microblog users to register under their real names to Guangdong, state media said Thursday, after a spate of violent protests in the southern province. The report, in the Southern Daily newspaper, comes as the Chinese government tightens its grip on the Internet in the face of rising social unrest that has been concentrated in the wealthy southern manufacturing heartlands. Last week, Beijing city authorities issued new rules requiring users of weibos -- microblogs similar to Twitter -- in the capital to register using their real names. Those regulations also apply to weibo operators based in Beijing, which include Sina -- owner of China's most popular microblogging service. If, as reported, they are extended to Guangdong, they will also apply to the operator of China's second-largest weibo user, Tencent. With more than half a billion Chinese now online, authorities in Beijing are concerned about the power of the Internet to influence public opinion in a country that maintains tight controls on its traditional media outlets. Despite official censorship of the web, Chinese citizens are increasingly using weibos to post pictures and reports of protests and other information that would normally not be reported by the country's state-run media. Until now, users have been able to set up weibo accounts under assumed names, making it more difficult for authorities to track them, and allowing them to set up new accounts if existing ones are shut down by censors.