Hong Kong's GDP in the second quarter saw only a 0.6 percent year-on-year increase, with retail and tourism bearing the blunt of the downward economic pressure, according to the HKSAR government.

On Monday, Hong Kong protesters staged a strike to paralyze Hong Kong by clogging public transportation, resulting in some 250 flights being canceled, and eight metro lines suspended for over five hours, he said. A total of 18 countries and regions have issued travel safety reminders against visiting Hong Kong due to the current situation.

Protesters also removed the Chinese national flag from a flagpole in Tsim Sha Tsui and threw it into the sea, the second incident of its kind in two days. The flags have since been recovered and raised.

In July, protesters tore up copies of the Basic Law of the HKSAR and smeared China's national emblem. They also broke into and vandalized Hong Kong's Legislative Council building, spraying graffiti on the walls and raising the former colonial flag.

"These acts have seriously violated the law, blatantly offended national dignity, and challenged the bottom line of the 'one-country, two systems' principle," Yang said. "These rioters are extremely arrogant and unscrupulous. What awaits them will be a heavy legal blow and an indelible shame in history."