U.S. Customs and Border Protection officials posted a video on social media Friday showing someone attempting to dismantle concertina wire along a section of the fence separating the U.S. and Mexico.
Officers say a U.S. Border Patrol thermal imaging camera captured the video on Wednesday at approximately 7 p.m. south of Imperial Beach, California.
What is unknown is who was on the Mexico side of the fence stepping on the wire and pushing it down to the ground.
On Thursday, U.S. Marines were guarding construction workers as they reinforced the fence that extends along the beach into the Pacific Ocean west of the San Ysidro Port of Entry, the busiest land border crossing.
Thousands of members of a migrant caravan have arrived into the area near Tijuana, Mexico since Sunday. Thousands more are expected to arrive over the next few days.
With U.S. border inspectors processing only about 100 asylum claims a day at the main border crossing with San Diego, prospects grew that migrants would be stuck waiting in Tijuana for months.
The waiting list for migrants requesting asylum has grown to more than 3,000 names with some individual waiting as many as six weeks to be interviewed.