China said violent protests in Hong Kong wouldn't be tolerated, in the Beijing government's most high-profile response to unrest rocking the Asian financial hub.

The Hong Kong and Macau Affairs Office, which answers to China's Cabinet, reaffirmed its support for the city's government and police in a rare briefing Monday in Beijing. Office spokesman Yang Guang said the country remained committed to the "one country, two systems" that has ensured the former British colony's autonomy since its return in 1997.

"What has happened in Hong Kong recently has gone far beyond the scope of peaceful march and demonstration, undermined Hong Kong's prosperity and stability, and touched on the bottom line of the principle of 'one country, two systems,'" Yang said. "No civilized society under the rule of law would ever allow acts of violence to take place."