The Department of Homeland Security (DHS) will no longer use horses at the Texas-Mexico border where thousands of Haitian migrants have tried to seek refuge.

"We have ceased the use of the horse patrol in Del Rio temporarily. We'll prioritize other methods for identifying individuals who might be in medical distress," CNN quoted a DHS official Thursday.

The department is investigating horseback Border Patrol agents in Del Rio, Texas, who appeared to be aggressively trying to push migrants back.

At least one agent was also heard taunting a migrant and used profanities to describe Haiti.

The U.S. has been flying migrants back to Haiti. On Thursday, officials said the camp has been reduced to 4,000 people, down from about 15,000.

Immigration officials said about 3,200 migrants have been processed into the U.S. system.

The U.S. is also in talks with Brazil in Chile to allow some Haitians who had previously been living in those countries to return, according to The Associated Press.