CNN  — 

The Taliban have moved swiftly to crush early opposition to their rule across Afghanistan, clashing with protesters and forcing an entire city to stay inside, as a frantic rush to escape the country intensifies at Kabul’s international airport.

A curfew will be imposed “for an indefinite time” over the entire southeastern Afghan city of Khost on Thursday, multiple Taliban sources told CNN on Wednesday, after videos emerged on social media purporting to show hundreds of people there demonstrating against the militant group’s seizure of power.

All kinds of movement will be banned “while joint forces of the Islamic Emirate carry out clearance operations” in the city, one source said. Around 650,000 Afghans are estimated to live in the rural and urban areas of surrounding Khost province.

The rapid shutdown of opposition undermines the Taliban’s repeated attempts to convince international media and observers that their rule will be more restrained and inclusive than it was two decades ago.

But it reflects the reality across the country, where similarly severe approaches have been taken.

Tensions are especially heightened because August 19 is Afghanistan’s Independence Day, commemorating the date Britain relinquished control of the country in 1919.

Taliban fighters patrol Kabul on Thursday, Afghanistan's Independence Day.