Chinese Internet users have reported greater difficulty accessing Gmail in recent weeks, prompting speculation that the Chinese government is again stepping up its efforts to control the flow of information on the Web.Gmail users are complaining on Chinese microblogs that the service has been slow or inaccessible. Google has reported no problems with access in China, but the complaints are ongoing and appear to have started late last month."Gmail access has been very poor in the last several days," Mark Natkin, managing director of Beijing-based Marbridge Consulting, said in an interview Monday. "And it doesn't appear to be related to the earthquake in Japan, as other friends immediately outside of mainland China have reported having no difficulty."A spokeswoman for Google said the service was having no technical difficulties. "There is nothing technically wrong on our side, so you will have to ask the government as it is clearly an issue on their end," the spokeswoman, Christine Chen, said in an e-mail. China routinely blocks overseas websites and takes down content it deems politically sensitive. But the problem with Gmail could mark a new tactic to disrupt services without blocking a site completely, said Bill Bishop, an independent analyst who watches China's Internet market. "The people behind the Great Firewall have clearly upped their game," he said.The Chinese government has been working hard to prevent the recent wave of politcal upheavel in the Middle East from breaking out at home. Chinese microblogs have barred users from searching for the term "Jasmine," for example, following calls by activists abroad for China to hold its own "Jasmine Revolution."China already blocks popular overseas sites like Twitter and Facebook, leading users to flock towards Chinese social media sites that comply with Beijing's strict censorship laws. Users in the country can still access Gmail, albeit less reliably in recent weeks. But the e-mail service was targeted last year by a hacking attack from China, which Google said was aimed at gaining access to the accounts of Chinese human rights activists. China's Internet censors were likely told "to squeeze even harder" given the government's success in stopping the unrest in the Middle-East from taking hold at home, Bishop said. "I don't think this is a new technology. I think this a policy decision," he said. It's difficult to know how much longer the latest problems with Gmail will last. Last month the U.S.-based social networking site LinkedIn reported being blocked. But only a day later the site could be accessed again from China. China's Internet censorship has prevented other Google sites from reaching Chinese users in the past. YouTube and Blogger are currently blocked in the country, and Google.com has occasionally been blocked for short periods."I think ultimately, if you can't access your e-mail you are going to switch e-mail providers," Bishop said. "We'll see. It's so hard to know what's going on with the way [the Chinese censors] work. ... Maybe things will chill out."