China vows crackdown on 'hostile forces' as public tests Xi

China's ruling Communist Party has vowed to "resolutely crack down on infiltration and sabotage activities by hostile forces," following the largest street demonstrations in decades staged by citizens fed up with strict anti-virus restrictions.

The statement from the Central Political and Legal Affairs Commission released late Tuesday comes amid a massive show of force by security services to deter a recurrence of the protests that broke out over the weekend in Beijing, Shanghai, Guangzhou and several other cities.

While it did not directly address the protests, the statement serves as a reminder of the party's determination to enforce its rule.

Hundreds of SUVs, vans and armoured vehicles with flashing lights were parked along city streets Wednesday while police and paramilitary forces conducted random ID checks and searched people's mobile phones for photos, banned apps or other potential evidence that they had taken part in the demonstrations.

The number of people who have been detained at the demonstrations and in follow-up police actions is not known.

While reports and footage of the protests have flourished online before being scrubbed by government censors, they have been ignored entirely by the strictly controlled state media.

Further diverting attention was Wednesday evening's national news dominated by the death of former president and Communist Party leader Jiang Zemin at the age of 96.