Updated

Beijing's Communist Party chief issued a veiled warning to Chinese internet portal Sina over its Weibo microblogging service after a visit to the company's headquarters, a sign of the government's growing anxiety over Weibo's explosive growth and spreading influence that threatens the government's media controls, The Wall Street Journal reported Wednesday.

Internet companies should "step up the application and management of new technology and absolutely put an end to fake and misleading information," Liu Qi, secretary of the Beijing Municipal Party Committee and a member of the party's powerful Politburo, told company executives during Monday's visit according to state media.

Footage broadcast on state-run Beijing TV Tuesday showed Liu and dozens of officials touring the Sina offices and getting an introduction to Weibo from CEO Charles Chao. Also on hand were former Google China head Kai-Fu Lee and Beijing real estate mogul Pan Shiyi, two of the most influential users of the service with more than six million followers each.

A blend of Twitter and Facebook, Weibo has become a social phenomenon in China by providing a platform for real-time, freewheeling discussion of everything from pop culture and celebrity gossip to news and politics. Sina announced last week that the number of registered accounts on the two-year-old service had climbed above 200 million -- an increase of roughly 40 percent over three months.

The high-level attention poses a dilemma for Sina, which does not want to fall foul of party propaganda officials, but whose commercial future increasingly depends on its ability to keep alive an edgy national discourse.

For example, Weibo recently served as a conduit for public indignation over the July 23 collision between two high-speed trains near the southeastern Chinese city of Wenzhou that killed at least 40 people and injured more than 190. Afterwards, millions of users flooded onto the site to exchange information and express frustration with the government's response.

Some analysts described the Wenzhou train crash as a watershed moment for Weibo. But many users have worried that it might eventually lead to a backlash, possibly even the shuttering of the service.