Migrants find an alternate place to cross between Mexico and the United States after access to a dam was closed, Sunday, Sept. 19, 2021, in Ciudad Acuña, Mexico. Credit: Sarah Blake Morgan / AP

DEL RIO, Texas — The United States blocked the Mexican border on Sunday at an isolated Texas town where thousands of Haitian refugees have crossed and set up a camp, hoping to stop the flow of migrants as officials also began flying some of the migrants back to their homeland.

About a dozen Texas Department of Public Safety vehicles lined up near the bridge and river where Haitians have been crossing from Ciudad Acuna, Mexico, into Del Rio, Texas, for almost three weeks. Yellow police tape is being used to block them from using a small dam to walk into the U.S.

A Mexican police officer on the Mexican side of the border said migrants won’t be allowed to cross anymore. He would not give his name.

Many of the migrants have lived in Latin America for years, but they are now seeking asylum in the U.S. as economic opportunities in Brazil and elsewhere dry up. Thousands are living under and near a bridge in Del Rio.

Earlier Sunday, the U.S. sent three flights of Haitians back to their homeland. The planes are expected to arrive Sunday afternoon in Port-au-Prince, Haiti’s capital.

Story by Juan A. Lozano, Eric Gay and Elliot Spagat, Associated Press. Associated Press writers Ben Fox, Alexandra Jaffe and Colleen Long in Washington and Danica Coto in San Juan, Puerto Rico, contributed to this report.