The U.S. is bracing for a surging influx of migrants arriving at its southern border with Mexico, including thousands of unaccompanied children who are being held in detention facilities that critics say are inhumane and cruel.

Nearly 18,900 unaccompanied migrant children were held at the southern border in March, the largest monthly number ever recorded, according to data from the U.S. Customs and Border Protection (CBP).

The March figure almost doubled the number of unaccompanied children caught at the border in February, and more than five times the number in March last year.

Four regions, including El Paso and Rio Grande, saw an over threefold increase in apprehensions in the past six months compared with the same period in fiscal 2020.

The record-breaking rise in migrant children arriving at the U.S.-Mexico border has left authorities scrambling for solutions to a growing humanitarian crisis.

Lawyers representing those migrant minors said the detentions facilities where the children are being held are cramped and overcrowded.

The children reported taking turns sleeping on the floor, not being able to call family members, and showering once in as many as seven days, Neha Desai, one of the lawyers, told the media earlier.

Images released last month from one of the detention centers in Texas showed children overcrowded in makeshift rooms, sleeping in foil blankets with inadequate access to food and clothes. The ill-suited facilities also raised concerns over a lack of social distancing during the COVID-19 pandemic.

The Los Angeles Times analyzed data of about 266,000 migrant children detained by the U.S. government in recent years, finding that more than 25,000 have been held in government custody for more than 100 days, and nearly 1,000 have spent more than a year.

As of last Wednesday, there were more than 20,000 unaccompanied minors in U.S. government custody – also a record high.

An internal document by CBP project that up to 184,000 unaccompanied children could arrive at the southwest border in fiscal year 2021, which began on October 1, 2020, according to Reuters. It would be higher than any other year on record since 2010, when CBP began to fully track apprehensions of unaccompanied children.

The U.S. border officials also estimated that the number of unaccompanied children held in government-run shelters could grow to 53,000 by September, underscoring a mounting crisis for the Biden administration.

Graphics: Qu Bo