Migrants have been detected in underground tunnels, posing a challenge to border enforcement. U.S. Customs and Border Patrol has shared video of these detections on their social media platforms. The footage shows migrants in underground crossings, highlighting the difficulties in securing these areas.

Further details about the underground tunnels and migrant detections are available from the source. The video posted by U.S. Customs and Border Patrol provides visual evidence of the issue, but additional information is needed to understand the full scope of the problem.

More information can be found through the original source, which may provide updates and insights into the ongoing efforts to address the challenge of underground crossings.