ROCKVILLE, Md. (AP) — Police in Maryland say they’re investigating two robberies where people offered items for sale online and were robbed when they met the supposed buyers in person.

Montgomery County police say in a statement that the unrelated robberies happened in the Wheaton area. Police say one robbery took place July 6 after a man offered a pair of tennis shoes for sale on Facebook’s “Marketplace.” Police say when the man met the alleged buyer the person produced a handgun and stole the shoes.

READ MORE: Baltimore City Councilman Zeke Cohen Arrested At CASA Protest In DC

Police say the second robbery took place July 8 and that the victim was a woman who had advertised a digital camera on the app “OfferUp.” Police say the woman was assaulted and robbed.

READ MORE: Gov. Larry Hogan Lifts All COVID-19 Capacity Restrictions As Of Saturday, Indoor Mask Mandate Will Remain

Police are urging residents to use so-called “exchange zones” at police stations for transactions.

Follow @CBSBaltimore on Twitter and like WJZ-TV | CBS Baltimore on Facebook

MORE NEWS: Colonial Pipeline Back Up, But It Could Take Days To Return To Normal Due To 'Panic Buying' Of Gas

(© Copyright 2017 The Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten or redistributed.)