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The number of unaccompanied immigrant children apprehended while illegally crossing into the United States has increased dramatically in the last few weeks, mostly in Texas. But Arizona is feeling some of the ripple effect, too.

Department of Homeland Security Secretary Jeh Johnson has declared a “Level IV condition of readiness because the current situation exceed the capacity” of Customs and Border Protection and Immigration and Customs Enforcement in the Rio Grande Valley. That has led some Arizona agents to temporary assignments in Texas.

Most migrants under 18 years old are from Guatemala, Honduras and El Salvador.

Homeland Security officials said the agency is advertising in Mexico and Central America to warn people of the dangers of crossing the border illegally, hoping to keep more youth from heading north.

An estimated 25,000 unaccompanied minors have been apprehended at the border, and by next year about 60,000 are anticipated, one official said.

“We are working on this situation since October, and it’s a concern for everybody for government organizations in Guatemala and in the United States,” said Jimena Diaz, consul general of Guatemala in Phoenix.

It is difficult to know why so many Central American teens are crossing into the U.S. but part of it could be lack of economic opportunities and misinformation about U.S. immigration policies, she said.

“We know that in Guatemala the smugglers tell parents that if their kids come here there is a way for their kids to stay and have no problem at all because they are young,” Diaz said.

Since 2011, apprehension of unaccompanied minors has doubled each year with the biggest increase so far coming this year, DHS officials said.

The Trafficking Victims Protection Reauthorization Act requires immigration officials to give custody of the children apprehended to the U.S. Department of Health and Human Services after processing their paperwork. Health and Human Services then handles repatriation or detention.

The average age of young immigrants crossing without parents or relatives has been between 14 and 18, but that is shifting to those as young as 9, said Lisa Frydman, associate director of the Center for Gender & Refugee Studies at the University of California Hastings College of the Law.

“Many unaccompanied minors have parents in the U.S. and they are coming to meet them,” she said, while also citing violence in their country as the main reason for migrating to the U.S.