WASHINGTON — Hundreds of migrants are being flown from South Texas to holding cells in California by the Department of Homeland Security, in a move that officials said on Friday could be expanded by sending asylum seekers to processing centers throughout the United States, including the border with Canada.

Customs and Border Protection officials said they began flying migrant families from overcrowded facilities in the Rio Grande Valley in Texas to San Diego on Tuesday. It is expected that as many as three flights, each carrying up to 135 migrants, will be scheduled each week.

The agency also recently started flying migrants five times each week from the Rio Grande Valley to Del Rio, Tex. Nearly all of the migrants are traveling as families, including some with young children.

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