About 10,000 migrants being held under bridge in Del Rio, Texas

About 10,000 migrants are packed under a bridge in Del Rio, Texas, waiting to be taken into U.S. custody, officials said on Thursday.

Customs and Border Protection is sending extra manpower to deal with the crush of migrants in the Del Rio Sector, the agency said in a statement to ABC News.

"The Border Patrol is increasing its manpower in the Del Rio Sector and coordinating efforts within DHS and other relevant federal, state and local partners to immediately address the current level of migrant encounters and to facilitate a safe, humane and orderly process," CBP said in a statement. "To prevent injuries from heat-related illness, the shaded area underneath Del Rio International Bridge is serving as a temporary staging site while migrants wait to be taken into USBP custody."

"Drinking water, towels, and portable toilets have been delivered for migrants to use while they await to be transported to a facility," CBP added.

The overwhelming majority of people held under the bridge at the Del Rio Sector are from Haiti, a source briefed on the situation told ABC News.

Del Rio Mayor Bruno Lozano said he had asked federal authorities to help quell the situation.

"Good evening from Del Río, TX. 10,503 (as of 6:45pm, September 16, 2021) migrants under the Del Río International Bridge. This morning we started at 8,200. President Biden, have you been briefed on the ongoing crisis yet," Lozano tweeted on Thursday.

Republicans have swiftly criticized the situation and blamed President Joe Biden.

Republican Sen. Ted Cruz filmed a video from under the bridge, posted on Twitter, saying, "This is a crisis that is unfolding. It's a man-made crisis."

"Local officials pleading with the Administration for help along the border," former President Donald Trump's acting Secretary of Homeland Security Chad Wolf tweeted. "This is absolutely insane."

Texas Gov. Greg Abbott criticized the Biden administration Thursday, saying it reversed its decision to close ports of entry after a massive influx of migrants arrived at the Texas border.

"Six hours after U.S. Customs and Border Protection requested help from Texas to close ports of entry and secure the border, the Biden Administration has now flip-flopped to a different strategy that abandons border security and instead makes it easier for people to cross illegally and for cartels to exploit the border," he said in a statement. "The Biden Administration is in complete disarray and is handling the border crisis as badly as the evacuation from Afghanistan. I have directed the Texas Department of Public Safety and the Texas National Guard to maintain their presence at and around ports of entry to deter crossings."

CBP apprehended just over 208,000 people at the southern border in August, down about 4,000 from July, according to federal data. CBP made just 50,014 apprehensions at the southern border in August 2020, when Trump was in office.