BEIJING - China's leader-in-waiting Xi Jinping, who has set off a storm of rumors after not showing up at scheduled public events for over a week, is nursing an ailment, possibly a back injury suffered while swimming, sources said on Tuesday.

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 US Secretary of State Hillary Clinton and the premiers of Singapore and Denmark.

China's government, however, has declined to spell out what is ailing Xi, 59 - in keeping with decades of official secrecy over the health of senior leaders, a tradition viewed in the West as out of step with a modern state and emerging superpower.

Please LIKE our Facebook page - it makes us stronger