Apprehensions of migrant families and unaccompanied children near the U.S.-Mexico border continued to skyrocket last month, with U.S. authorities detaining or turning away more than 140,000 people — including about 84,000 families and 11,000 minors.

"We're in a full-blown emergency," U.S. Customs and Border Protection (CBP) acting commissioner John Sanders told reporters Wednesday.

Border officials turned away more than 11,000 adults, families and children and detained nearly 133,000 migrants between ports of entry along the southwestern border. In addition to the large number of children and family units, authorities also apprehended more than 36,000 single adults.

A chart from Customs and Border Protection shows the number of migrants apprehended and turned away at the border since 2014. Customs and Border Protection

The apprehensions in May — the highest monthly total in 13 years — represent the latest marker of an unprecedented flow of families and children from Central America journeying towards the southern border that has overwhelmed border officials for months. Sanders said his officers have apprehended or turned back nearly 700,000 migrants in the past eight months.

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May is the fourth consecutive month in which the number of families apprehended has reached a record-high under the tenure of President Trump, who has threatened to impose tariffs on Mexican goods unless the country's government does more to stop migrants from El Salvador, Honduras and Guatemala — a region known as the "Northern Triangle" — from reaching the U.S.

Administration officials said the apprehensions in May underscored a major concern for them: dwindling space in housing and detention facilities for migrants along the border. They said they expect the large-scale migration to continue, even during the summer months when there are typically fewer apprehensions because of the sweltering hot weather in many parts of Central America, Mexico and the southwestern U.S.

CBP forecasts the total number of apprehensions will top 1 million for the fiscal year ending in September, a number that has not been reached since 2006. Additionally, detentions of unaccompanied minors — which stands at nearly 55,000 for fiscal year 2019 — is on track to surpass the 67,339 apprehensions registered in 2014, when the Obama administration faced a surge of unaccompanied migrant children from Central America at the U.S.-Mexico border.

The projection by CBP officials is also likely to further strain the resources of the Department of Health and Human Services (HHS), which is responsible for taking care of migrant children after they are detained by Border Patrol. On Wednesday, the agency said it was preparing to end all educational, recreational and legal services offered to migrant children in its custody, warning Congress that it is running out funds to take care of unaccompanied minors.

Angel Canales contributed to this report.