SUGAR LAND, Texas -- Several employees were tied up during a robbery at a Sugar Land cell phone store on Thursday, KPRC Local 2 reported.

Fort Bend County sheriff's deputies said three men robbed a T-Mobile store in the 9700 block of Highway 6 shortly before 5 p.m.

The men looked around the store and asked about upgrading their service. When one of the clerks tried to help them, two of the men pulled out guns, investigators said.

Detectives said the men demanded the "good" phones and camera tapes.

Two clerks got down on the ground and crawled to an office where the men bound them with plastic zip ties, deputies said.

Investigators said a third employee, who was already in the office, was ordered to open a safe that the phones in sealed boxed were stored in.

The man put the phones, valued at about $50,000, in a black trash bag, officials said.

Deputies said one of the men is Indian, 20 to 25 years old, about 5 feet 6 inches tall and about 150 pounds. He has a thin build, dark complexion, short black hair and a full mustache and beard. He was last seen wearing a red-and-blue cap, a white shirt with the number "05" on it, black jean shorts, white socks, black slippers and eyeglasses.

Another one of the men is Asian, about 5 feet 1 inch tall and about 140 pounds. He has brown hair with a bald spot in the middle. He was last seen wearing a red shirt, blue jean shorts, white ankle socks and black shoes.

The third man is Hispanic, 20 to 25 years old, 5 feet 3 inches to 5 feet 6 inches tall and about 200 pounds. He has a heavy build and short, curly, black hair. He was last seen wearing a black T-shirt with "ARMY" on it, black pants, white shoes and eyeglasses.

Detectives said the men are likely responsible for several other robberies at T-Mobile stores throughout Houston.

Anyone with information is asked to contact Fort Bend County Crime Stoppers at 281-342-TIPS.