HOUSTON -- Houston police released surveillance pictures Monday of two males wanted in connection with a crime spree of cell phone stores, KPRC Local 2 reported.

Police said four or five men are suspected of at least nine robberies since Jan. 13.

The crimes occurred at the following locations.

Jan. 13 at 11307 Bissonnet
Jan. 18 at 11303 Wilcrest
Jan. 19 at 8104 Southwest Freeway
Jan. 21 at 2600 South Kirkwood
Jan. 21 at 11660 Westheimer
Jan. 22 at 12542 Bellaire Blvd.
Jan. 25 at 2505 State Highway 6
Feb. 2 at 11316 Westheimer
Feb. 9 at 514 Elgin

In each case, the robbers were armed when they entered the stores and demanded personal property from everyone, as well as cell phones and cash.

The crooks covered their faces and heads with bandanas, masks or hooded sweatshirts.

They threatened to shoot employees and customers if the victims did not comply with their demands.

The robbers were seen leaving one of the heists in a purple, four-door Saturn.

Witnesses described the two pictured suspects as black males, between 16 and 20 years old, 5 feet 7 inches to 6 feet tall, weighing between 140 to 180 pounds.

Anyone with information is asked to contact the HPD Robbery Division at (713) 308-0700 or Crime Stoppers at (713) 222-TIPS.