HOUSTON -- Harris County sheriff’s deputies need help to find three men suspected in four robberies at Cash America Pawn Shops in northeast Harris County, KPRC Local 2 reported Friday.

Deputies said the trio walk into the Cash America Pawn Shops near closing time with their faces covered by ski-masks or bandanas.

They demand money from the cash drawers and safes, detectives said.

Detectives said that in one robbery, the men forced the customers in the store to empty their pockets and stole personal items from them. In another robbery the group stole several guns from a display case.

"These men are getting more and more dangerous because they take control of the workers and the customers and are not scared to point their gun," Sgt. Curtis Brown said. "They might hurt someone next time."

The robberies occurred on July 31at the store located at 717 Normandy, on Aug. 4 at the store located at 9801 Airline and on Aug. 5 at the store located at 13837 Nimitz. The same men may also be involved in a fourth robbery that is being investigated by the Houston Police Department. That one happened on Wednesday at the store located at 5219 Airline.

Witnesses to one of the robberies told investigators that they saw the trio get into a silver car, possibly a Mazda.

Anyone with information is asked to call Crime Stoppers at 713-222-TIPS. Crime Stoppers and Cash America is offering a reward of up to $15,000.