China warns Hong Kong protesters against playing with 'fire'

China warned Hong Kong's pro-democracy protesters Tuesday that "those who play with fire will perish by it", a day after the most widespread unrest of the two-month crisis.

In its harshest warning yet Beijing said the immense strength of the central government should not be underestimated as police in the semi-autonomous city announced they had arrested 148 people in connection with Monday's violence.

The city has been plunged into chaos by weeks of protests triggered by opposition to a planned law that would have allowed extraditions to mainland China. The protests have since evolved into a wider movement for democratic reform and the protection of freedoms.

At a press briefing in Beijing, Yang Guang, spokesman for the Hong Kong and Macao Affairs Office of the State Council, said the "radical protests... have severely impacted Hong Kong's prosperity and stability, pushing it into a dangerous abyss".

Yang said the government still "firmly supports" both the Hong Kong police force -- who have been criticised for their handling of the protests -- and Carrie Lam, the city's pro-Beijing leader who protesters want to resign.

"We would like to make it clear to the very small group of unscrupulous and violent criminals and the dirty forces behind them: Those who play with fire will perish by it," Yang said.

"Don't ever misjudge the situation and mistake our restraint for weakness... Don't ever underestimate the firm resolve and immense strength of the central government."