Border Patrol apprehend 33,335 illegal border crossers last month and saw an uptick in apprehensions of “unaccompanied children” and so-called “family units.”

According to Border Patrol data released Friday, of the total 33,335 total apprehensions at the border in March, 4,201 were “unaccompanied children” and 4,448 were “family units” or at least one adult traveling with children.

Total apprehensions in March represented a 28 percent increase over February’s apprehension level of 26,076.

The apprehensions of “unaccompanied children” and “family” units also increased 37 percent and 46 percent, respectively, compared to February. The apprehensions in March still remained lower than, to-date, this fiscal year’s peak in December when 6,765 minors and 8,974 adults with children flooded across the southern border.

In recent years the southern border has experienced a surge in illegal immigration by “unaccompanied children” — many of whom are in their teens and on the cusp of adulthood — and “family units” largely from Central America.

While immigration activists and Democrats argue that “push” factors in the migrants’ home countries have forced the northern movement, Republicans and immigration hawks say the Obama administration’s lax immigration enforcement policies and amnesty policies have served as an enticement for illegal immigration.

The influx of minors traveling without a guardian and “families” reached a fever pitch in 2014 when more than 68,541 minors and 68,445 “families” were apprehended at the southern border and overwhelmed the government’s capacity. The vast majority remain in the U.S., ostensibly awaiting immigration proceedings.

The Obama administration says the government remains on high alert for a repeat of 2014, although levels still remain strikingly higher than years prior to FY 2012.

“The Department of Homeland Security continues to closely monitor current migration trends and is working aggressively to address underlying causes and deter future increases in unauthorized migration, while ensuring that those with legitimate humanitarian claims are afforded the opportunity to seek protection,” Border Patrol noted with its data release. “We also continue to support broader regional efforts to address the humanitarian situation in Central America.”

Most of the apprehended “family units” and “unaccompanied minors” are released into the interior of the U.S. with notices to appear in immigration court, many simply abscond.

According the Senate Subcommittee on Immigration and the National Interest, just 3.6 percent of the “unaccompanied children” apprehended illegally entering the U.S. over the past 2.5 years have been sent back to their home countries. The remaining 96.4 percent are still in the U.S.