【明報專訊】REGARDING the National People's Congress's (NPC) decision to enact the ''Law for Safeguarding National Security in the Hong Kong SAR'', Secretary for Security Lee Ka-chiu has revealed that the police are setting up a new unit that will be in charge of enforcing the new law. The national security bill has yet to be unveiled. It is true that its exact provisions are an important matter of concern. But what worries Hong Kong people most is the mechanism for enforcement. The NPC resolution mentions that the central government will set up an agency for national security in Hong Kong ''if need be''. It remains to be further clarified whether the new unit dedicated to the new law as suggested by Lee will play a main role in the enforcement of the law or a supporting role as a counterpart of the mainland's national security agency in the city. If clarification about the scope of authority of the national security agency in Hong Kong is made as soon as possible and it is guaranteed that the local agency enforcing the law will abide by the principles of common law, it will be vital to the dispelling of public doubts.