Unaccompanied immigrant children held in crowded, smelly cells at Texas Border Patrol facility

Thousands of immigrant children who have entered the U.S. illegally are being held in crowded, foul-smelling holding cells in South Texas until they're transferred to shelters.

Customs and Border Protection officials offered a tour Wednesday of an overcrowded Border Patrol station in Brownsville. It was the first tour of the station since President Barack Obama called the more than 47,000 unaccompanied children who have come this budget year an "urgent humanitarian situation."

Most of the immigrants being held at the Fort Brown station are teenagers and children. They are held in concrete cells and sleep on the floor.

The minors were caught crossing the border amid a surge of immigration from Central America in recent weeks. They are processed in Brownsville and Nogales, Arizona, before being transferred to shelters and then reunited with family members in the U.S.