CHICAGO (CBS) — Police are warning about a string of robberies on the city’s Southwest Side, which are occurring at buildings under rehab.

LISTEN: Newsradio 780’s Mike Krauser Reports

In each case, armed robbers enter the building while contractors are working, announce a robbery, and steal anything they can from the workers.

So far, there have been 14 such robberies since September. They have occurred mostly on Western and Kedzie avenues, between 58th and 73rd streets.

Police advise caution, and advise everyone to be aware of suspicious people loitering in the area of the robberies.

They also advise contractors to keep the buildings where they are working secure, evaluate the security of the building for unauthorized entry points, be careful not to show valuables or large amounts of cash, and call 911 immediately to report anyone or anything suspicious.