LOS ANGELES >> Thieves have been raiding cargo containers aboard trains nearing downtown Los Angeles for months, taking packages belonging to people across the U.S. and leaving the tracks blanketed with discarded boxes.

The packages are from retailers including Amazon, REI and others, CBSLA reported Thursday. The sea of debris left behind includes items that the thieves apparently didn’t think were valuable enough to take.

While CBSLA cameras were on the scene, one person was spotted running off with a container used to hold small packages, and a Union Pacific railroad police officer was spotted pursuing two other people who were apparently going through packages.

The scene was the same in November, when NBC4 showed thousands of boxes discarded along the tracks lined with homeless encampments northeast of downtown in the Lincoln Park area.

Passing trains carried containers with doors wide open and packages tumbling out, NBC4 reported. Video showed two men, one holding what looked like bolt cutters, walking along the tracks, the station said.

Union Pacific said in a statement to CBSLA that the railroad was concerned about increased cargo thefts in California.

“We have increased the number of Union Pacific special agents on patrol, and we have utilized and explored additional technologies to help us combat this criminal activity. We also will continue to work with our local law enforcement partners and elected leaders,” the railroad said.