A border policeman stands next to a barbed wire wall on the Bulgarian border with Turkey, near the village of Golyam Dervent on July 17, 2014. Overwhelmed by an influx of mostly Syrian immigrants, Bulgaria has taken steps to secure its EU border -- including building a barbed-wire fence -- but now faces criticism from rights groups. The 30-kilometre (19-mile) fence, standing three metres (10 feet) high and fortified with razor wire coils, was completed this week. Covering the least visible section of Bulgaria's 275-kilometre (170-mile) border with Turkey, it aims to stem a flow of refugees that saw more than 11,000 people enter the country illegally last year -- 10 times the annual figure before the Syrian conflict.   AFP PHOTO / DIMITAR DILKOFF        (Photo credit should read DIMITAR DILKOFF/AFP/Getty Images)
DIMITAR DILKOFF/AFP/Getty Images
A border policeman stands next to a barbed wire wall on the Bulgarian border with Turkey, near the village of Golyam Dervent on July 17, 2014. Overwhelmed by an influx of mostly Syrian immigrants, Bulgaria has taken steps to secure its EU border -- including building a barbed-wire fence -- but now faces criticism from rights groups. The 30-kilometre (19-mile) fence, standing three metres (10 feet) high and fortified with razor wire coils, was completed this week. Covering the least visible section of Bulgaria's 275-kilometre (170-mile) border with Turkey, it aims to stem a flow of refugees that saw more than 11,000 people enter the country illegally last year -- 10 times the annual figure before the Syrian conflict. AFP PHOTO / DIMITAR DILKOFF (Photo credit should read DIMITAR DILKOFF/AFP/Getty Images)
Now playing
01:52
150 agents deployed to Texas border
AirTag
Apple
AirTag
Now playing
01:17
See AirTag, Apple's new device for tracking your lost stuff
ABC/Fremantle North America/19 Entertainment
Now playing
01:27
Katy Perry consoles 'Idol' contestant after he flubs lyric
NASA/JPL
Now playing
01:29
Watch the Ingenuity helicopter's first flight on Mars
Marvel Entertainment
Now playing
01:13
Marvel introduces first Asian superhero in new trailer
Consumer Product Safety Commission
Now playing
01:08
Video shows child getting caught under Peloton treadmill
CNN
Now playing
02:56
Watch Anderson Cooper belly laugh with Cheri Oteri
Brooke Baldwin last show goodbye CNN newsroom vpx_00000217.png
CNN
Brooke Baldwin last show goodbye CNN newsroom vpx_00000217.png
Now playing
03:56
'Get a little uncomfortable': See Brooke Baldwin's last words on air
US Navy
Now playing
01:28
Pentagon confirms UFO video is real, taken by Navy pilot
Now playing
01:24
How Kyra Sedgwick got the cops called on Tom Cruise
Fancy Feast/Purina
Now playing
01:06
Cat food company makes a cookbook ... for humans
Google Earth's new timelapse feature
Google
Google Earth's new timelapse feature
Now playing
01:09
Google Earth's new Timelapse feature shows 40 years of climate change in just seconds
Twitter | @brady9dream
Now playing
02:10
Pet owners pitch their pups to be dog brew's 'Chief Tasting Officer'
FOX/"The Masked Singer"
Now playing
01:23
'The Masked Singer' reveals identity of The Orca
LONDON, ENGLAND - DECEMBER 07:  A visual representation of the digital Cryptocurrency, Bitcoin on December 07, 2017 in London, England. Cryptocurrencies including Bitcoin, Ethereum, and Lightcoin have seen unprecedented growth in 2017, despite remaining extremely volatile. While digital currencies across the board have divided opinion between financial institutions, and now have a market cap of around 175 Billion USD, the crypto sector coninues to grow, as it continues to see wider mainstreem adoption. The price of one Bitcoin passed 15,000 USD across many exchanges today taking it higher than previous all time highs.  (Photo by Dan Kitwood/Getty Images)
Dan Kitwood/Getty Images
LONDON, ENGLAND - DECEMBER 07: A visual representation of the digital Cryptocurrency, Bitcoin on December 07, 2017 in London, England. Cryptocurrencies including Bitcoin, Ethereum, and Lightcoin have seen unprecedented growth in 2017, despite remaining extremely volatile. While digital currencies across the board have divided opinion between financial institutions, and now have a market cap of around 175 Billion USD, the crypto sector coninues to grow, as it continues to see wider mainstreem adoption. The price of one Bitcoin passed 15,000 USD across many exchanges today taking it higher than previous all time highs. (Photo by Dan Kitwood/Getty Images)
Now playing
03:10
Bitcoin has an energy problem
The new all-electric Mercedes-EQS
Mercedes-Benz AG
The new all-electric Mercedes-EQS
Now playing
01:05
See the new all-electric EQS luxury sedan from Mercedes

Story highlights

Apprehensions at the border are surging, Homeland Security chief says

The agents are being sent to South Texas amid a surge in migrants

(CNN) —  

US Customs and Border Protection is sending 150 extra agents to the Rio Grande Valley in South Texas as authorities report a surge in the number of undocumented children and families trying to cross into the United States from Mexico, the agency said Saturday.

In October, 46,195 people were apprehended on the border, compared to 39,501 in September and 37,048 in August, Department of Homeland Security Director Jeh Johnson said in a statement earlier this week.

“As a result, there are currently about 41,000 individuals in our immigration detention facilities – typically, the number in immigration detention fluctuates between 31,000 and 34,000,” he said.

The extra agents are being assigned work in the immigrant processing centers in McAllen and Weslaco, Customs and Border Protection said in a news release. The move should free up local agents who are more familiar with the region, the agency said.

The extra agents are coming from the areas of Tucson, Arizona; San Diego; and Del Rio, Texas. They are expected to arrive as early as Sunday and will probably remain in South Texas at least two months, said Chris Cabrera with the National Border Patrol Council.

Stories from a desert bus station

That part of Texas saw a surge of unaccompanied and undocumented children and families the summer of 2014, many of them from Honduras, Guatemala and other Central American nations.

Unaccompanied minors have been trekking to the United States in steadily increasing numbers since 2012, according to the nonpartisan Migration Policy Institute.

Johnson said Immigration and Customs Enforcement is seeking additional detention space to hold single adults so they can be returned quickly to their home countries.

“Those who attempt to enter our country without authorization should know that, consistent with our laws and our values, we must and we will send you back,” Johnson said. “Once again, I encourage migrants and their families to pursue the various safe and legal paths available for those in need of humanitarian protection in the United States.”

CNN’s Khushbu Shah and Polo Sandoval contributed to this report.