Absent "crown prince" is nursing swimming injury, claim Chinese CHINA'S leader-in-waiting, Xi Jinping, who has set off a storm of rumours after not showing up at public events for more than a week, is nursing an ailment, possibly a back injury suffered while swimming, Chinese government sources have said. Mr Xi, who is due to take over the presidency of the world's second-largest economy in March, has skipped several meetings with visiting foreign leaders and dignitaries over the past week, including US secretary of state Hillary Clinton and the prime ministers of Singapore and Denmark. China's government, how­ever, has declined to spell out what is ailing Mr Xi, 59. "He injured his back when he went for his daily swim," a source close to the Beijing leadership said after Mr Xi's absence from the public stage was first noticed last week. The source declined to give further details on the injury, including exactly when and where the incident took place. Another source said the injury happened when Mr Xi went swimming. He pulled a [back] muscle when he went swimming. The lack of an official explanation has fuelled internet speculation surrounding Mr Xi's condition and brought some pointed questions at briefings by China's foreign ministry. Yesterday, the ministry's spokesman, Hong Lei, was asked whether Mr Xi is in good health. Sticking to his government's usual reticence, Mr Hong said he had no information to give. But he appeared dismissive of any hint that Xi might be in a bad way. "I hope you can ask a serious question," he said when asked to confirm Mr Xi was alive. China's popular microblogging site, Sina Weibo, blocked searches for Mr Xi's name, as is common with top leaders, but users as usual found ways to skirt the restrictions, referring to Mr Xi as "the crown prince." What's up with the crown prince? He's vanished for the last 10 days or so and the whole world is wondering where he is," wrote one user. Despite the rumours, some of China's top officials continued to travel outside Beijing - not what would be expected if the leadership was in crisis. Premier Wen Jiabao gave a speech in the northern port city of Tianjin, and vice-premier Li Keqiang was visiting a north-western region. The rumours about Mr Xi come at a tempestuous time for Chinese politics. The 18th Communist Party Congress is set to take place in October. Earlier this year, senior politician Bo Xilai was suspended from the Politburo and his wife convicted 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.