HONG KONG — Hong Kong International Airport — sleek, modern and famously efficient — has helped symbolize the city’s stature as one of the world’s busiest and most important commercial hubs since it opened more than two decades ago.

But this week the airport, long a source of local pride, became the epicenter of civilian unrest as anti-government protests escalated. For the second day in a row, the airport suspended check-ins on Tuesday as thousands of protesters occupied parts of the departure and arrival halls.

Demonstrators blocked check-in gates, and the police wielded batons and pepper spray. Unhappy passengers scuffled with protesters as voices, and tensions, rose. Tourists scrambled to gather bags and usher children away from the restive crowd.

[Chaos at the airport as pleas for order are ignored.]

Not too long ago, such scenes would have seemed unthinkable at the airport, the world’s eighth busiest and its largest air cargo center, with more than five million metric tons passing through in 2018. While large-scale protests have become a regular occurrence in Hong Kong this summer, the airport had remained mostly unaffected.