New laws against computer crimes and external interference are among those proposed under Article 23 of the Basic Law.

Speaking at a press conference on Tuesday, Secretary for Security Chris Tang said the government will improve existing laws and propose new offences in its consultation paper, and that Article 23 will have extra-territorial powers.

Under the proposals, the new laws criminalise treason and related acts; insurrection, inciting mutiny and disaffection, and acts with seditious intention; theft of state secrets and espionage; sabotage endangering national security and related activities; and external interference and organisations engaged in activities endangering national security.

Secession and subversion are not included because they are already covered under the National Security Law.

Tang said there will be a new offence prohibiting acts in relation to a computer or electronic system without lawful authority and endangering national security, targeting sabotage of public infrastructure.

"Under existing offences such as damaging property and accessing computers with dishonest intent, we are proposing a new offence to target offences that endanger national security, so that we can address such risks and strengthen deterrence and crack down on acts that endanger national security through such acts," he said.

Another new offence is to prohibit anyone from working with outside forces to influence local affairs, such as the city's elections and judicial decisions.

The security minister added that laws banning incitement to disaffection against the police and the Government Flying Service would be expanded to cover a wider range of officials, including policymakers, officials who manage public finances and the judiciary.

On the extra-territorial powers of the laws, Tang said acts and activities endangering national security, regardless of whether they are carried out in or outside of Hong Kong, would be punished, and the proposals fully align with international law and conventions.

The consultation paper also said that the authorities could consider introducing measures to ensure that law enforcement agencies have sufficient time to carry out investigations when dealing with national security cases.

It noted that the UK, for example, has given the police the power to apply for an extension of the period of detention of national security suspects.