The US State Department issued a travel advisory Wednesday for Hong Kong, urging “increased caution” due to the ongoing civil unrest.

Flights resumed Wednesday at Hong Kong’s airport after two days of clashes between riot police and pre-democracy demonstrators at one of the world’s busiest air hubs.

“Since June 2019, several large scale and smaller political demonstrations have taken place in various areas of Hong Kong, including at Hong Kong International Airport,” the State Department said in a release.

“Most have been peaceful, but some have turned confrontational or resulted in violent clashes. Police have used a variety of crowd control measures, including the deployment of tear gas,” the statement continued.

“The protests and confrontations have spilled over into neighborhoods other than those where the police have permitted marches or rallies. These demonstrations, which can take place with little or no notice, are likely to continue.”

The advisory comes as protesters and police faced off Wednesday night outside a police station in Hong Kong’s residential Sham Shui Po area, where a vigil was taking place, according to CNN.

Riot police fired tear gas at a group of protesters who had gathered to burn phony currency and incense as a way to show their opposition to police during the month-long Hungry Ghost Festival, when offerings are made to fend off the spirits of ancestors.

Heavily armed police marched through the neighborhood, where they fired tear gas at the retreating protesters.

Meanwhile, the State Department urged Beijing on Wednesday to allow Hong Kong to “exercise a high degree of autonomy,” amid speculation that Chinese troops could enter the territory to quell the unrest.

“The United States is deeply concerned by reports of Chinese paramilitary movement along the Hong Kong border. The United States strongly urges Beijing to adhere to its commitments in the Sino-British Joint Declaration to allow Hong Kong to exercise a high degree of autonomy,” the department said.

“As the President noted, we urge all sides to engage peacefully and refrain from violence. We encourage China and all parties in Hong Kong to pursue a solution that respects the liberty of Hongkongers and Hong Kong’s high degree of autonomy, as enshrined in the Sino-British Joint Declaration.”

With Post wires