Officials reported Monday 6,500 Haitians and other migrants have been expelled from an encampment in Del Rio, Texas. The video shows the migrants crossing the Rio Grande back and forth between the United States and Mexico.

Most are being flown back to Haiti. “Border Patrol is coordinating with ICE and the U.S. Coast Guard to move individuals from Del Rio to other processing locations, including approximately 3,500 over the last few days and 3,000 today, in order to ensure that migrants are swiftly taken into custody, processed and removed from the United States, consistent with our laws and policies,” Department of Homeland Security Secretary Alejandro Mayorkas said. “We are working to increase the capacity of return flights to Haiti and other destinations. We anticipate at least one to three flights per day.”

Mayorkas said 600 Homeland Security employees, including the Coast Guard, have been brought to Del Rio. He also said he has asked the Defense Department for additional help.

The ongoing efforts to remove migrants could become one of the swiftest, large-scale expulsions of migrants and refugees from the United States in decades.

“We are communicating, as we have now for months, loudly and clearly, that irregular migration, the perilous journey, is not the journey to take,” Mayorkas said in a message to the expelled migrants. “One risks one’s life, the life of one’s loved one’s for a mission that will not succeed.”

Monday’s update comes a day after the Senate’s parliamentarian said Democrats can’t use part of their $3.5 trillion package to give millions of immigrants a chance to become citizens.

The rejected provisions would create a path for legal permanent residence or even citizenship for young immigrants brought illegally to the country as children. Those immigrants are commonly known as “dreamers”.

The provisions would also impact immigrants with Temporary Protected Status who’ve fled countries stricken by natural disasters or extreme violence, essential workers and farm workers.

In a three-page memo to senators, Parliamentarian Elizabeth MacDonough said under Senate rules, provisions are not allowed in budget bills if their budget effect is “merely incidental” to their overall policy impact. She said the language of the provisions “is by any standard a broad, new immigration policy.”