The sheriff's office called it a "random act of violence."
Deputies responded to the 8700 block of Airline Drive near Gulf Bank Road, where Sheriff Ed Gonzalez said in a tweet that three people had been shot.
According to an update from officials early Monday morning, a man driving in the parking lot fired several rounds.
Two of the people who were struck were transported to the hospital. All three victims are expected to survive.
The shooter is on the run, and there's no description of his vehicle.
Police told ABC13 they are reviewing surveillance video.
This latest shooting on Airline makes eight shootings on Houston-area roadways in the past six days.