The way the United States pulled out is "dishonorable, and a horrible breaking of promises ... and leaving thousands of people behind that we promised we'd take out with us including American citizens," Eubank, who is from Free Burma Rangers and provides humanitarian services in war-torn areas, told CBN News.

In some instances, the pull-out has been "cowardly," he continued, speaking from Tajikistan, which neighbors Afghanistan and where many Afghans are arriving after fleeing the Taliban.

"They [the Taliban] are hunting down people right now, trying to get all the names of anyone they perceive as an enemy," Eubank said, adding that the enemies include "people who work with the U.S. government, people who are with other governments, people who work with non-governmental organizations they don't agree with."

Eubank, who is in Tajikistan to help Afghans, also said that "many have been executed. ... I've seen recent photos of 30 to 40 people [being executed]."

Eubank clarified that he doesn't know the scale of the killings or the arrests, "but I believe it's countrywide now."

The Taliban are allowing American citizens who have identity cards to escape, he continued, adding that "anyone who doesn't have papers, anyone they perceive as an enemy, they are going to arrest them, and, in many cases, execute them."

The people in Afghanistan "are in terror," Eubank added.

According to its website, Free Burma Rangers have helped 1.5 million displaced persons to date who would have otherwise died.

In an interview with The Christian Post last year, Eubank shared: "I am motivated by what Jesus does for me and want to share His love and encourage people to follow Him. We are not to be led by comfort, fear or pride, but go in the love God gives us. We go into areas of direct combat to save lives and share love."

Following the drawing down of U.S. troops in Afghanistan, the Taliban quickly seized control of much of the country, taking the capital Kabul last month and forcing the government to flee.

The U.S.-based persecution watchdog International Christian Concern warned last week that as the Taliban is cracking down on protests and journalists, concerns are also being raised among religious minorities of increased oppression and persecution because the Taliban have promised strict enforcement of Sharia law.

Almost all Afghan Christians -- estimated to be between 8,000 and 12,000 -- are converts from Islam and remain largely closeted and hidden from the public eye due to severe persecution.

"Their status as converts makes Afghan Christians direct targets for persecution by both extremist groups and society in general," ICC reports. "In Afghanistan, leaving Islam is considered extremely shameful and converts can face dire consequences if their conversion is discovered."