(WTVO) — American war veterans conducted a daring secret mission in Kabul to rescue hundreds of Afghan Special Forces troops and their families.

According to the Daily Mail, the group of former Green Berets and SEAL Team members launched a mission called “Pineapple Express,” named after an Afghan commando they had served with, who contacted them to say he was on the run from the Taliban.

In the original phase of the mission, the spec ops team told their contacts to go to the airport and identify themselves with the password “pineapple,” or a photo of a pineapple on their smartphone, to be put on a plane.

According to ABC News, the group began a daring raid into Kabul at nightfall on Wednesday, working unofficially with US military to move people, sometimes one at a time, inside the US controlled airport.

The mission was underway Thursday when the airport was attacked by ISIS fighters, who killed 13 US servicemembers and wounded 15 others.

The Task Force Pineapple group said they had moved as many as 630 Afghans to the airport as of Thursday morning.

Former Navy SEAL Jason Redman, who was working with the group to extract Afghans he knew, said “that our own government didn’t do this. We did what we should do, as Americans.”

“That is an astounding number for an organization that was only assembled days before the start of operations and most of its members had never met each other in person,” Capt. Zac Lois said.

Lois told ABC News he modeled the system of maneuvering Afghan families after Harriet Tubman’s Underground Railroad.

“I have been involved in some of the most incredible missions and operations that a special forces guy could be a part of, and I have never been a part of anything more incredible than this,” Gant told ABC News. “The bravery and courage and commitment of my brothers and sisters in the Pineapple community was greater than the U.S. commitment on the battlefield.”