Daimler AG and BMW AG’s joint car-sharing and mobility business suspended service in Chicago after a fraud incident.

As of Wednesday evening, 100 vehicles were unaccounted for, and law enforcement believes 50 of them, all Mercedes-Benz models, are still in the Chicago metropolitan area, Luis Agostini, a Chicago police spokesman, said in an emailed statement. More than a dozen persons of interest are being questioned, he said.

Earlier Wednesday, police said some vehicles may have been rented using deceptive means through Share Now’s mobile app. Multiple vehicles had been recovered, police said at the time.

The Share Now service wasn’t hacked, said Mike Silverman, a company spokesman. He declined to comment on details of the incident due to there being an ongoing police investigation.

Share Now -- formed when Mercedes-Benz maker Daimler AG and BMW AG combined their Car2Go and DriveNow businesses this year -- is working with law enforcement to address the issue, which is isolated to Chicago. While members’ personal information hasn’t been compromised, it’s pausing service out of precaution, Silverman said.

This article was provided by Bloomberg News.