(CNN) -- A tide of border crossings by children mostly from Central America is not expected to end soon, and some in Congress blame President Barack Obama for policies they claim opened the floodgate. Holding centers in Texas can no longer accommodate large numbers of children and mothers traveling alone with their kids, forcing the federal government to open additional facilities. One is in Nogales, Arizona, where pictures of unaccompanied children lying on the floor of a large barren facility raised concerns of a humanitarian crisis. But Nogales Mayor Arturo Garina said the site, which serves as an overflow center for up to 1,000, is addressing the immediate need for shelter.
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Up to 400 unaccompanied children are crossing the Texas border each day
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Most of the children are coming from Honduras, El Salvador and Guatemala
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Overflow holding facilities have been opened to accommodate the youth
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Nogales, Arizona, Mayor says the facilities are "better than expected"
@placeholder has been so overwhelmed that federal officials are transporting busloads of immigrants, including minors, to Arizona.