Masked thieves brokes into a car dealership in the Portage Park neighborhood on the Northwest Side early Tuesday but police say they were unable to find keys for any of the cars. 

Just before 1:40 a.m., a security company monitoring the cameras of the dealership in the 5200 block of West Irving Park Road noticed five masked men were inside the business, police said.

One of the men got in through a broken window of a service door, and he then let the other robbers into the business, police said. 

The men were not able to find the keys to the vehicles and they weren't able to leave with any cars, police said. 

No one was in custody. 

On Sunday, five cars valued at more than $205,000 were stolen from a Libertyville dealership Sunday night and later were involved in a high-speed chase in Wisconsin, according to Libertyville police officials.

Sunday's heist came after six cars were stolen on Feb. 13 from an Infinity dealership in Clarendon Hills, four BMWs and a Porsche were stolen Feb. 3 from the Autobarn Mazda in Evanston and five luxury cars were stolen in late January from a Mercedes dealership in Glencoe.

Our editors found this article on this site using Google and regenerated it for our readers.