ANN ARBOR, Mich. -- Ann Arbor police said a string of home break-ins might be linked to case of a stolen set of master keys.

The keys were stolen during a break-in of a car belonging to an employee of Arch Realty, which manages several rental properties for the University of Michigan.

Ann Arbor police Lt. Myron Blackwell said the keys can provide access to hundreds of properties across the city.

"This involves over 238 properties of Arch Realty and probably about a thousand residents," Blackwell said.

The company sent an e-mail to residents, alerting them to the fact that there have been several break-ins where it appears entry wasn’t forced.

The company said they are in the process of re-keying properties.

So far, there have been two confirmed break-ins at homes accessible with the stolen keys. Witnesses reported seeing two men who drove a dark gray Saturn.

While police have alerted people living near those rental properties about the suspect vehicle, police patrols have been increased in those neighborhoods with high concentrations of properties managed by Arch Realty.