Federal investigators are offering $2,500 rewards for tips leading to people who set fires inside Walmart stores in Alabama and Mississippi.

The FBI posted Saturday security camera photos of masked people inside stores in Mobile, Alabama, and Gulfport, Mississippi. News outlets report firefighters extinguished a fire inside the Mobile store on May 28, and investigators concluded an accelerant was used to fuel it. No one was injured.

Two fires were reported Friday inside a Walmart store in Gulfport. Gulfport police spokesman Jason DuCre told WALA-TV that investigators suspect the same people are responsible for the Gulfport and Mobile fires.

The FBI is asking people in Alabama with information to call 251-438-3674. Those with information about the Mississippi fires are asked to call that number or 601-948-5000.