China's parliament has backed security legislation for Hong Kong which would make it a crime to undermine Beijing's authority in the territory.
Clashes broke out on Wednesday as Hong Kong's parliament debated a different proposed law, which would make it a crime to disrespect the Chinese national anthem.
Hundreds of people were arrested in protests over that and the security law.
Full details about exactly what behaviour will be outlawed under the new security law are not yet clear.
That meant that Hong Kong no longer merited being treated differently from the mainland under US law.
That means China could potentially have its own law enforcement agencies in Hong Kong, alongside the city's own.
Under the same agreement, Hong Kong had to enact its own national security law - this was set out in Article 23 of the Basic Law. »