The U.S. Border Patrol has detained fewer unaccompanied children entering South Texas illegally in the past 10 days, agency officials said Thursday.

In recent months, the Border Patrol's facilities in South Texas have been overwhelmed by a surge in the number of children entering the country without their parents. More than 57,000 children have been arrested since October, more than double the number compared to a year earlier.

The Border Patrol's Rio Grande Valley sector Chief Kevin Oaks made the comment about declining child arrests following a media tour of a new processing facility for them in McAllen. The 55,000-square-foot converted warehouse is scheduled to open Friday and temporarily house as many as 1,000 children until they can be turned over to the Health and Human Services Department and sent to shelters.

"We arrested 80 juveniles yesterday, so within the last 10 days we've seen a decrease in the number of juveniles arrested," Oaks said. Later, Roel Rodriguez, the agent who will head the new processing facility, said that daily arrest tally was down from 200 to 300 unaccompanied children at the surge's height.

Children arrested after entering the U.S. without their parents posed a challenge for the Border Patrol. Its stations are equipped only with simple holding cells and not intended for extended stays. When agents began arresting more children than could be quickly processed they backed up stations in the Rio Grande Valley, forcing the agency to bus and fly detainees to other parts of Texas and out of state.

Oaks' comments jibe with a general drop in total immigrant arrests in South Texas in the final week of June. The Border Patrol has not released such data for July, but weekly arrest totals included in law enforcement intelligence reports obtained by The Associated Press in May and June show that arrests dropped in the final week of June to a level not seen since mid-May. Weekly arrest totals in the Rio Grande Valley during those months peaked in mid-June at more than 9,000. The factors contributing to the drop are unclear and it is unknown if it will continue.

Oaks said that with the opening of the McAllen facility, the Border Patrol was winding down a similar processing center in Nogales, Arizona, and he expected it to close within a week. The vast majority of the children enter the U.S. in South Texas and the new processing facility is just around the corner from the region's busiest Border Patrol station. Law requires the Border Patrol to turn the children over to HHS within 72 hours of their arrest.

He said his sector now had fewer than 200 unaccompanied children in custody, compared to as many as 1,200 on any given day during the peak.

The children, mostly from Honduras, Guatemala and El Salvador, are fleeing widespread gang violence and poverty in their home countries. Some come to reunite with parents already in the U.S., while others flee for their lives. Some parents have said they've heard rumors that the children will be allowed to remain in the U.S. and the government tries to reunite children with relatives in the U.S. while they wait for their cases to be heard.

Generally, the children have been turning themselves in to the first official in a uniform they see after crossing the Rio Grande.

President Barack Obama has requested $3.7 billion in emergency spending to deal with what he termed "an urgent humanitarian situation." That request increasingly appears in jeopardy as Democrats and Republicans clash over how to remedy the situation.

The new McAllen facility was set up inside a leased warehouse. Tall chain-link fences divide it into four "pods," each capable of holding up to 250 children. Children will sleep on small green mattresses, receive medical screenings and have common areas to watch television.

"The issue is very complex. We're not talking about criminals or anything," Oaks said. "These are innocent children fleeing desperate times whether it's poverty, whether it's violence, whether it's the draw of a better life the United States, whether it's family reunification."