DEARBORN, Mich. – The FBI is investigating a string of jewelry store robberies nationwide, including Mariam Jewelry in Dearborn.

The suspects appear to wear Halloween masks and carry weapons.

Mariam Jewelry, a family-owned business, was robbed by gunmen on Aug. 7.

FBI Assistant Special Agent In Charge Christopher Hess said they believe this robbery was part of a more significant trend.

“There is information and belief that this may be tied to an armed robbery crew who engaged in robberies in Illinois as well as Missouri,” Hess said.

The other robberies occurred at jewelry stores in Bridgeview, Illinois, and Winchester, Missouri.

“It seems to be their MO (Modus Operandi) that they’re wearing, I would say, a Halloween-style mask,” Hess said.

The FBI is offering a reward of up to $15,000 for information leading to an arrest in the case.

Since the robbery at Mariam Jewelry in Dearborn, the shop has added enhanced security measures, including bullet-proof glass and an extra set of locked doors to exit and enter the building.

“They need to catch this network because it’s dangerous for us and for other people,” Ali Alasadi, who works at Mariam Jewelry, said.

If you have any information concerning these individuals, please contact the FBI’s Toll-Free tipline at 1-800-CALL-FBI (1-800-225-5324).

You may also contact your local FBI office, the nearest American Embassy or Consulate, or you can submit a tip online at tips.fbi.gov.

Videos provided by the Federal Bureau of Investigation can be found below: