Last Wednesday, after Mr. Xi did not meet Mrs. Clinton and Prime Minister Lee Hsien Loong of Singapore , diplomats said privately that he had a bad back. Xi, who is due to take over the presidency of the world's second-largest economy in March next year, has skipped several meetings with visiting foreign leaders and dignitaries over the past week, including U.S. Secretary of State Hillary Clinton and the prime ministers of Singapore and Denmark. Hong Lei, a Chinese Foreign Ministry spokesman, declined to say whether a meeting with Mr. Xi had been scheduled and then canceled, telling a regular news briefing Monday: "As agreed between the Chinese and Danish sides, leaders of China's State Council will meet the Danish prime minister." “I hope you can ask more serious questions,” Hong Lei told reporters in Beijing after being asked if Mr Xi was even still alive. Chinese leaders sometimes don't appear in public for extended periods, with no explanation, but it is very unusual for one to cancel meetings with foreign officials at such short notice, according to party insiders, diplomats and political analysts. “But no one is saying anything.” 
 
 Advertisement Continue reading the main story 
 
 Mr. Xi’s absence comes during a year when the Chinese political system has suffered serious blows. Plans for a smooth leadership transition have already been thrown into disarray by the scandal surrounding Bo Xilai, the ousted party leader who was once a candidate for the top leadership but whose wife, Gu Kailai, was convicted last month of murdering a British businessman. In another scandal this month, a senior ally of President Hu Jintao was demoted after sources said the ally's son was involved in a deadly crash involving a luxury sports car. The 18th Communist Party Congress, at which China's next top leaders including Xi are likely to be unveiled, is set to take place in October. Popular Internet search sites have aggressively removed references to Mr. Xi and have even blocked searches for “back injury.” 
 
 One well-connected political analyst in Beijing said that Mr. Xi had suffered a mild heart attack but that it was not serious enough to prevent him from assuming China’s top positions. As if to assuage worries about Mr. Xi’s health, a newspaper on Monday ran a picture of Mr. Xi addressing students at the opening of the fall semester of the Central Party School. So far, however, state media have made little attempt to suppress the rumors surrounding Mr. Xi, although one party newspaper, Study Times, did put on its front page Monday a transcript of the speech he made at his Sept. 1 appearance.
– The global rumor mill is swirling around the sudden conspicuous absence of Xi Jinping, who is scheduled to ascend to China's presidency in a matter of weeks. Xi hasn't been seen in public in 10 days, according to the Telegraph, and last week he took the unheard of step of canceling three meetings with top foreign officials, including Hillary Clinton. Yesterday, officials turned journalists away from a planned photo-op between Xi and Denmark's prime minister, denying it had ever been scheduled. Officials tell Reuters Xi hurt his back while swimming, but speculation of worse is rampant. One source tells the New York Times that Xi may have suffered a mild heart attack, and an earlier report, since retracted, alleged that a military official tried to assassinate him, and wound up injuring him in a car accident. Amid the speculation, China has blocked all Internet searches for his name, the Wall Street Journal reports. "Something is amiss," a Brookings Institute member says. "Otherwise, they would have found an opportunity for him to be seen.