Authorities were called around 1:20am to Jack's Place on Veterans Memorial near Fallbrook. They found an employee with a gunshot wound in the foot.
Witnesses say a group of up to five men entered the business, demanded money and fired their weapons. Several customers were inside. They were robbed as well.
A pending investigation will look into the business itself.
"Our vice division is handling whether it's illegal or a legal operation," said Sgt. David Hillborn with the Harris County Sheriff's Office.
The employee's injuries are considered non-life threatening. The suspects remain on the run.