LOS ANGELES (AP) — Authorities say dozens of handguns and shotguns were among items stolen by thieves who raided cargo containers aboard trains near downtown Los Angeles for months.

The Los Angeles Times reports police arrested three people last summer carrying new .22-caliber handguns. A trace of the weapons revealed they came from a batch of 36 handguns reported missing as they were being shipped by train to Tennessee.

Police say shotguns were also stolen, but it’s unclear how many.

The cargo thefts gained national attention earlier this month after local TV stations showed images of thousands of discarded boxes from stolen packages blanketing the tracks. Thieves had been raiding cargo containers aboard trains nearing downtown for months.

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.

Luis Rosas, who makes about $20 an hour working for a company subcontracted by Union Pacific to salvage items from the tracks in the Los Angeles area, said he’s encountered the brazen thieves in action before. Using bolt cutters, they break locks on the containers and load up vans or trucks with the stolen merchandise.

Rosas has been doing this work almost daily for about six months and while he’s been told not engage in confrontations, he still feels afraid.

“They don’t even run off anymore. They do it right in front of us,” he told The Associated Press earlier this month, wearing a bright yellow vest before he headed to work to pick up car tires along the tracks. “At first I was shocked. I was amazed by it.”