(CNN) On the day she died, the little girl was thousands of miles away from the country where she was born.

An Arizona medical examiner said Friday that 6-year-old Gurupreet Kaur had died of hyperthermia . Temperatures in the area where agents found her remains Wednesday hovered around 108 degrees.

Her death highlights a rarely discussed reality that's been playing out at the US-Mexico border in recent years: A growing number of migrants from India have been crossing there.

The number of Indian nationals apprehended at the Southwest border has been steadily climbing, and sharply increased last year, according to Border Patrol statistics . In the 2018 fiscal year, 8,997 people from India were apprehended at the Southwest border -- more than triple the number from the year before, when 2,943 Indian migrants were apprehended.

A larger trend

That's still a small percentage -- about 2% of the overall number of migrants apprehended at the Southwest border in fiscal year 2018. The clear majority of migrants apprehended at the border came from Latin American countries, largely from Mexico, Guatemala, Honduras and El Salvador.

But the increase in Indians apprehended is notable. And it's part of a larger trend.

"There has been a pretty significant increase in general in migrants coming from other continents. It's not just Indians, says Jessica Bolter, a research assistant at the Migration Policy Institute who tracks migration patterns at the border.

An increase in Indian nationals and other migrants from outside the Western Hemisphere illegally crossing the US-Mexico border has been "an emerging trend for the past few years," a Department of Homeland Security official told CNN Friday.

The apprehensions of migrants from Bangladesh at the southwest border also increased significantly from fiscal year 2017 to fiscal year 2018, nearly doubling from 564 to 1,198.

US Customs and Border Protection officials have recently highlighted the cases of groups of African migrants apprehended in Texas , noting that groups that arrived recently were primarily made up of families from the Republic of the Congo, the Democratic Republic of the Congo and Angola.

"With this girl from India, there hasn't been confirmation that she was traveling in a family, but it's likely," Bolter said. "This trend of increased family migration is echoing not just throughout Central America, but also beyond even the Americas. It indicates the message that families can enter the US easily is spreading."

Increase in apprehensions

But Bolter says migrants from outside the Americas have been making their way to the US-Mexico border for at least the past decade.

"They generally tend to fly in to places like Brazil or Ecuador, places that have more lax visa policies, and then continue on smuggling routes up north through Central America and Mexico to the US," Bolter says.

In 2019, she says, the number appears to be climbing as overall numbers of families apprehended at the border increase.

"The number of migrants being apprehended at the border from other continents has already doubled compared to last year," she says.

Department of Homeland Security officials have been sounding the alarm for months over what they describe as a humanitarian crisis at the border and a significant shift in who is illegally crossing it.

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Overcrowded Border Patrol facilities are packed not with the single men from Mexico who once made up most of the border-crossers, but primarily with Central American families and unaccompanied children, many of whom are seeking asylum.

Unaccompanied children and family members made up the majority of apprehensions in May, with more than 11,000 unaccompanied children and more than 84,000 family members taken into custody, CBP officials said earlier this month.

Trump administration officials say the skyrocketing numbers are more proof for the case they've been making for months: Loopholes in the US immigration system, they say, are encouraging a growing number of migrants to come. Democrats argue the administration itself is to blame and that its policies have exacerbated the crisis.

Acting Homeland Security Secretary Kevin McAleenan defended the Trump administration's actions at the US border at a Senate hearing Tuesday and accused Congress of dragging its feet.

"This crisis is unlike anything our country has ever faced," he said.