(Reuters) – The disappearance of China’s defence minister, the latest in a string of upheavals in the country’s top ranks, is stoking uncertainty about President Xi Jinping’s rule as an internal security clampdown trumps international engagement.

Defence Minister Li Shangfu, who has missed meetings including with at least one foreign counterpart since he was last seen in late August, is under investigation in a corruption probe into military procurement, Reuters reported on Friday.

As Xi, China’s commander-in-chief has focussed inward, he caused concern among foreign diplomats this month by missing a Group of 20 summit in India, the first time he has skipped the global leaders’ gathering in his decade in power.