The Standing Committee of the National People's Congress (NPC), China's top legislature, began to review the draft national security law for Hong Kong on Thursday.

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The draft clarifies the specific composition of four types of criminal acts and stipulates relevant criminal responsibilities. The four types of crimes are secession, subversion against the state power, terrorist activity, as well as collusion with foreign forces that endanger national security.

The draft was submitted to the 19th session of the 13th NPC Standing Committee on Thursday for the first deliberation.

The NPC approved a decision on May 28 during its annual session in Beijing to establish and improve the legal system and enforcement mechanisms for the Hong Kong Special Administrative Region.

The decision authorized the Standing Committee to draft the exact wording of the national security law for Hong Kong.

READ MORE: Six things you need to know about HK security legislation