Washington (CNN) Arrests of migrant families and unaccompanied children at the southern border reached record highs over the past year, driven by a surge in asylum seekers, acting Customs and Border Protection Commissioner Mark Morgan announced Tuesday.

The figures provided showed the dramatic spike in border apprehensions throughout the year, as well was an increase in seizures of all hard narcotics and new record high of travelers processed through customs.

The crush of migrants at the southern border this past fiscal year -- totaling nearly 1 million, Morgan announced this month -- overwhelmed US officials. The influx led to overcrowding at facilities and in some cases, deteriorating conditions, raising concerns within the agency and among lawmakers and immigrant advocacy groups.

The US Border Patrol apprehended 473,682 family members last fiscal year, up from 107,212 in fiscal year 2018. Additionally, 76,020 unaccompanied children were taken into custody on the US-Mexico border, which was higher than any year on record -- including the 2014 surge of unaccompanied children

"These are numbers that no immigration system in the world can handle, not even in this country. And each month during the fiscal year, the numbers increased. You saw them. We all saw them," Morgan said.

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