The Taliban faced new defiance Thursday against their takeover of Afghanistan and dispersed peaceful protesters with deadly force, while the U.S. said more diplomats were arriving at Kabul’s airport to clear out the backlog of Afghans and U.S. citizens seeking to flee the country.

In the capital and other cities, hundreds of demonstrators came out Thursday, championing the red, green and black flag of the republic newly ousted by the Taliban. They waved the flag, an emerging symbol of resistance against Taliban rule, chanting, “Our flag, Our pride” and “God is Great.”

U.S. officials said they were maintaining channels of communication with Taliban commanders in an effort to ease the way for U.S. citizens, Afghan visa holders and applicants to reach Hamid Karzai International Airport. As many as 6,000 people had been processed and were waiting at the airport Thursday for military flights.