FORT LAUDERDALE, Fla. -- Postal inspectors are trying to figure out who broke into several mail trucks and stole mail from them.

The U.S. Postal Service has had several South Florida mail delivery trucks broken into at around the same time: one on March 8, another on March 10, another on March 21 and again on March 28.

A postal inspector says mail was stolen from the trucks twice.

Jim Hammers, who lives in Fort Lauderdale, says last month he mailed out several pieces of mail, but some of the checks never made it to the intended recipients.

"All of my checks didn't get there until recently, and one of them never got there," Hammers said,

He says the same thing happened to his girlfriend.

"All of her checks that she sent -- 18 checks -- only 3 got to their intended destination. Fifteen checks never arrived at their destination," Hammers said.

Hammers said he dropped his mail in a receptacle. Now, he believes the truck that picked it up was broken into.

"I had two checks (that) State Farm that didn't get until, like, three weeks later," Hammers said. "My policy was just about canceled. I had checks to my credit card company that didn't get there."

"You put a letter in the mailbox, you think it's going to get to the destination," he said.

Hammers has since filed a complaint with the Postal Service.

Although the inspector won't say where the break-ins happened, she says the Fort Lauderdale Police Department has increased security in those areas.

If you believe your mail may have been stolen, you can call the postal inspection service at (954) 436-7200.