China said on Monday it had lodged a protest with Singapore after Singaporean armored troop carriers were seized by Hong Kong customs en route back from Taiwan, as a state-owned newspaper warned against Singapore's "hypocrisy."

The nine troop carriers were impounded in Hong Kong last week, sparking a rebuke to Singapore from China's foreign ministry about maintaining military ties with self-ruled Taiwan, which China considers a breakaway province.

"China has already made representations over this to the Singapore side," Foreign Ministry spokesman Geng Shuang said at a regular news briefing on Monday.