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.