At least six people were transported to hospitals with injuries, CNN quoted Houston Office of Emergency Management spokesman Michael Walter as saying.
An emergency alert from the city warned residents to avoid the scene at a strip mall parking lot near the corner of Weslayan Street and Bissonnet.
There are no reports of additional suspects, police said.
"We have several with extremity injuries," an official told reporters. "We have a couple that are more serious."
A nearby homeowner told Fox News that his wife woke up to gunshots at 6.30 a.m. Shortly thereafter, police were seen going into a nearby condo.
One witness told ABC13 that the shooter fired three or four shots into the front window of her car and also shot the side window of the vehicle. Initial reports indicated seven people were hurt before police revised the number to six.
"As I was driving by Law Street I suddenly heard a big explosion," another witness said. "I covered myself, accelerated and tried to get out of there. I did not know if someone was following me or trying to shoot me."
A Houston Police Department bomb squad was at the site of the shootings after a suspicious vehicle, believed to belong to the suspected shooter, was discovered ABC13 reported.
The shooting comes days after a shooting at a Washington state mall that left five people dead. On September 17, a 20-year-old man stabbed 10 people at a Minnesota mall before being shot dead by an off-duty police officer.
