Thousands of migrants have arrived at the international bridge in Del Rio, Texas, over the past week, with Border Patrol agents struggling to process new arrivals.
A federal source told Fox News that at least 9,300 migrants are now camping under the bridge.
Bill Melugin with Fox News reports most are Haitians.
Val Verde County Sheriff Joe Frank Martinez told the Texas Tribune, "Border patrol is overwhelmed. They just can't process them fast enough, so there's a backlog of these individuals underneath the bridge."
Customs and Border Protection said it is working to send additional agents to the area.