Chinese President Xi Jinping has made a rare public reference to a recent crackdown which saw the country's top military general removed.

General Zhang Youxia, who was widely seen as Xi's closest military ally, was removed from his post in January. He was accused of "serious violations of discipline and law" - typically a euphemism for corruption.

Speaking in a virtual address on Tuesday, Xi said the past year had been "unusual and extraordinary", adding that the army had "undergone revolutionary tempering in the fight against corruption".

Since coming to power, President Xi has launched waves of anti-corruption drives, which critics say have also been used as a tool to purge political rivals.

In his remarks on Tuesday, Xi also added that the People's Liberation Army (PLA) had effectively addressed "various risks and challenges", adding that many in the army had gone through "in-depth political rectification".