China threatened to “resolutely crack down” on “hostile forces” as historic protests continued overnight — including wild street battles with riot cops clad in hazmat suits.

Communist Party leaders gave the ominous warning without directly mentioning the countrywide rallies, the largest show of dissent in the 33 years since protests in Tiananmen Square ended in horror and bloodshed.

Tuesday’s warning came as protests continued despite a heavy-handed crackdown by cops with the threat of lengthy prison sentences.

The anger that started with protests against China’s brutal “zero-COVID policies” — but widened to calls for President Xi Jinping to step down — has led to at least 43 protests in 22 cities, according to Australia’s ASPI think tank.

One clip showed dozens of police clad in white hazmat suits holding shields over their heads as they advanced in formation over what appeared to be torn-down lockdown barriers as objects flew at them.

The wave of protests stemmed from simmering frustrations over China’s “zero-COVID” policy that — three years into the pandemic — still leaves millions under lockdown and quarantine, limiting their access to food and medicine while ravaging the economy and severely restricting travel.