HARRIS COUNTY -

A search is underway for three men wanted in a violent armed robbery spree in northwest Houston. Investigators say the thieves robbed a burger restaurant and a gas station.

According to investigators, the Shell gas station is the latest to be robbed by masked gunmen. Authorities are looking to see if this may be related to a string of robberies in the area.

"That's terrifying. You think you're safe, but you never know," said Jessica Vaughn, who works next door.

Vaughn says she was frightened to hear that a couple of armed masked men barged into Smashburger looking for cash.

"This is a nice, quiet place," Vaughn said.

Deputies say Monday evening's crime spree started when two men carjacked someone, then drove to the upscale shopping center off Highway 249 and Louetta around 8:30 p.m.

"It being in the Vintage area, you don't ever think that it could happen," said Holly Lowe, who lives next door.

About 15 minutes later, investigators say the same two men robbed the Shell gas station, and even took the clerk's wallet.

Just last week police say masked gunmen robbed at least seven area businesses all in the same part of town. There have been dozens more since December.

"There's over 40 robberies that we have loosely linked together," said Lt. Nigel Stepchinski, of the Houston Police Department.

The Harris County Sheriff's Office didn't get back to Local 2 when asked if they're working with HPD on these possibly related cases. However, HPD does acknowledge a potential link.

"Based on suspect description and their methods of committing the robberies, we are looking at them as being related," said Lt Stepchinksi.

Investigators are now reviewing the surveillance footage taken from last night's robbery at Shell.

They hope that will help them identify the men who may be responsible.

Anyone with information on these crimes is asked to call the Harris County Sheriff's Office or Crime Stoppers at (713)-222-TIPS.