(NewsNation) — The number of migrants showing up at the U.S.-Mexico border, as has been reported numerous times by various media outlets, just keep growing.

What’s not so well known or reported is where some of those migrants wind up after crossing into the U.S. A source sent NewsNation videos of migrants at the border being loaded onto charter flights at the El Paso Airport, alleging they were then flown to various cities around the country.

We wanted to see it for ourselves, so we flew to El Paso and got a hotel next to the airport. We started tracking the charter flights, noticing that many would just vanish from tracking websites.

The only way to really find the pieces to the puzzle, we figured, was to show up to the airport and simply wait. At about 7 a.m. Monday, we spotted the charter planes.

It wasn’t easy. The area at El Paso Airport where the planes park is the only part of the airport where there are screens preventing onlookers from seeing what’s going on. But we did find an opening where there is a gate and we could see two charter flights parked next to each other with those government buses staging next to them.

Our camera crew zoomed in and filmed as busload after busload of migrants were loaded onto two planes — men and women shackled, frisked and closely guarded by Immigrantion and Customs Enforcement agents. Online tracking websites showed the flights were headed to Alexandria, Louisiana, and Harrisburg, Pennsylvania.

In Alexandria, ICE has a processing facility where migrants are detained and often deported.

While working on this story, El Paso police showed up and said someone from the airport complained that we were filming. However, we were able to stay in place because we were on a public sidewalk.

We also received a tip that migrants also leave from a different section of the airport, so we went there and observed a couple of parked buses. More buses showed up, and they waited for more than two hours until another plane arrived.

The buses then drove out onto the tarmac, and we watched as busloads of young people got onto a 737. At one point, the buses tried to block our view.

Airport workers say the flights happen daily — anywhere from two to four times a day — with a combination of young and old passengers.

One flight we watched took off for Jacksonville, Florida, and NewsNation cameras were there when it landed. Migrants got off the plane and were herded back onto buses. They stopped at a rest area off of I-95 before continuing south.

NewsNation reached out to ICE and Health and Human Services, which coordinates the migrant flights.

HHS told NewsNation they have a legal requirement to provide for the care and custody of all unaccompanied children, but they did not elaborate on flights. ICE also did not answer Entin’s questions about the flights.

Pennsylvania Congressman Dan Meuser is sponsoring a bill demanding more transparency about the flights and exactly where the migrants are going. He says the American people deserve to know.

“HHS has misled me or lied to me several times,” Meuser said. “I have asked, they actually told me any flights coming into Pennsylvania, we will notify you and the local schools. They didn’t. They haven’t notified us once.”

The migrant flights are not new. While the number of flights may be on the rise due to the surge at the border, the flights themselves have been used by prior administrations.

The federal government reportedly pays charter airlines to move migrants. Some with criminal backgrounds go to detention facilities. Unaccompanied minors go to shelters throughout the U.S.

“This is not new. This is a part of everyday procedures. There is nothing mysterious or nefarious. In order for children to move from border towns to shelter care facilities, they are going to have to travel. They are going to have to fly or go on buses,” said Essey Workie, with the Human Services Initiative.

Workie served as a senior federal official with the HHS and is now a director at the Human Services Initiative. She says the flights and bus trips can be especially traumatizing for unaccompanied minors who don’t know exactly where they will end up.

“In my conversations with some unaccompanied children, they have told me those were the worst three days of their entire experience and they felt mistreated by some of the staff, scared, and alone and uncertain about what was to come,” Workie said.

With Title 42 slated to end in just a matter of days, the flights are expected to ramp up even more, with a new surge of migrants arriving at the border being flown to cities across the country.