Use of the terrorism label for the Hong Kong protests, even in a somewhat backhanded way, is a major rhetorical shift in how China has described the protests, and could foreshadow an escalation in Beijing's handling of them.

Earlier today, a top Chinese official said the protests -- now in their eleventh week -- had "begun to show signs of terrorism." In recent years, that term has only been used in a domestic Chinese context to refer to the actions of alleged Islamist groups, particularly in Xinjiang, the predominantly Muslim northwest region of China. Beijing has cracked down heavily in Xinjiang in recent years, establishing a massive system of so-called "re-education camps" in which millions of Muslims have been detained.

In domestic propaganda, there has been a major shift in recent weeks in how the protests are covered. Reports initially barely mentioned them, amid heavy censorship, as is usual for anti-government actions anywhere in China, but increasingly they have emphasized the violent side of the protests -- and sought to paint the protesters as separatists being controlled by the United States and other foreign "black hands."

Suggesting those protesters are also committing acts of terror could open the door for Beijing to crack down on Hong Kong, either by ordering the local police to escalate their use of force, or even by deploying the People's Liberation Army (PLA) in the city.

The PLA can be deployed in Hong Kong if the local government requests it, in order to assist with a major breakdown in public order. Local officials have previously refuted any suggestion they would do so.

Earlier Monday, police showed off a riot control vehicle with water cannon, previously never used in Hong Kong. Across the border in Shenzhen, the People's Armed Police, a paramilitary organization, conducted major exercises seen as a potential signal to protesters in Hong Kong.