A rash of thefts from USPS mail collection boxes, first reported at the end of last year, continues to be a problem in some West Philadelphia neighborhoods, according to media reports. Thieves have recently broken into unidentified mailboxes, stole checks, and fraudulently cashed them for thousands of dollars, according to a report by CBS Philly. The amount in one of the stolen and cashed checks was changed from 40 dollars to 3,000, according to the report.

Thefts from USPS mailboxes have been occurring mostly in and around the zip code 19143, sometimes multiple times from the same mailbox. Last December, neighbors reported mailbox break-ins and thefts of checks, DVDs and letters/forms containing some personal information from mailboxes in Garden Court, Spruce Hill and Cedar Park neighborhoods in West Philly.

Although mail theft is a “very serious issue,” it’s still very rare and people should trust Postal Service mailboxes, George Clark, the U.S. Postal Inspection Service rep, told CBS.

West Philadelphia-elected officials, City Councilmember Jamie Gauthier and State Rep. Rick Krajewski, are also aware of the problem and working with the USPS to make mail collection boxes more secure. Residents whose mail has been stolen are encouraged to report the theft on a Mailbox Incident form here.

And here are some tips for those who are planning to send checks, cash or other valuable items via USPS:

Please don’t put your mail in USPS blue mail collection boxes on weekends, when there is no collection, and hold it off until Monday. Also please check the time of the collection on the mailbox you want to use. Or bring your mail to your neighborhood post office and drop it in the mail collection box inside.