A woman entered the store and asked where the restroom was located. When she came back to the front, officials said she placed several beverages on the counter along with a demand note.
The demand note stated she was armed with a gun, police said.
According to investigators, the note also said the store had been rigged with explosives and the place would explode if anything happened.
In the note, the woman demanded cash and a pack of cigarettes.
In fear for their lives, the clerks immediately ran to a safe room.
The suspect fled in an unknown direction.
The woman was described as a white female, 45-55 years of age, around 5 feet 7 or 8 inches tall and weighing 180-200 pounds. She had short brown hair and was wearing a red shirt and blue jean pants, officials said.
Anyone with information about who or where the woman may be is urged to call Crime Stoppers at 713-222-TIPS. All tipsters remain anonymous.