EAGLE PASS, Texas (NewsNation) — Agents at the U.S.-Mexico border apprehended 53 migrants, 37 of whom were rescued, while attempting to cross the Rio Grande River near Eagle Pass, Texas as part of a mission that also led to the discovery of the bodies of eight migrants, according to a source.

Six of the bodies were found by U.S. agents and two were discovered by officials with the Mexican government.

The source told NewsNation that Border Patrol agents are coordinating with the Eagle Pass Fire Department and the Maverick County Sheriff’s Office to search for more potential victims.

The Del Rio sector, which includes Eagle Pass, is fast becoming the busiest corridor for illegal crossings at the southern border, with thousands reaching the country each week. The sector may soon surpass Texas’ Rio Grande Valley, which has been the focus of immigrants for the last decade.

The Associated Press contributed to this report.