(DEL RIO, Texas) -- After more than a week of growing controversy, immigration authorities in Del Rio, Texas, on Friday finished clearing out an encampment of mostly Haitian migrants that at one point expanded to about 15,000 people.
"As of this morning, there are no longer any migrants in the camp, underneath the Del Rio International Bridge," Homeland Security Secretary Alejandro Mayorkas said at a White House briefing Friday afternoon.
Five flights departed Del Rio for Haiti on Thursday carrying 548 Haitians, officials said.
So far, more than a dozen flights have taken about 2,000 people back to Haiti, according to the Department of Homeland Security. About 3,900 have been moved from the camp for processing or expulsion.
The U.S. government has not accounted for all the migrants in the camp, but officials on Thursday said "several thousand" had returned to Mexico. Other government officials who spoke directly to ABC News but were not authorized to officially provide the information said "thousands" more have been placed in "removal proceedings" and released in the U.S.
Those proceedings can take time, officials said, in part because migrants in removal proceedings are legally allowed to make a claim of asylum. Asylum cases can take anywhere from six months and several years with the massive case backlog at immigration courts across the country.
The administration is also employing a controversial process of rapid removal or “expulsion" known as Title 42 -- a reference to a section of U.S. public health code that the government says requires them to immediately expel unauthorized migrants at the border.
Immigrant advocates have raised concerns about Title 42 cutting off access to legal means of obtaining asylum.