Ten to 15 passengers aboard flight 1031, which took off from Panama City, were hurt, the department said. Three passengers were taken to Houston hospitals, though firefighters did not know their conditions.
United Airlines said in a statement that nine customers and one crew member were transported to the hospital.
"Our thoughts and concerns are with those who were injured and our team is reaching out directly to our customers to provide further care and support," the brief statement concluded.
The airline has yet to respond to a question about whether Tropical Storm Cindy, which churned through the Gulf of Mexico on Tuesday afternoon, played a role in the turbulence. The Houston Press has also asked whether pilots altered the route of 1031 in an attempt to avoid hazardous weather.
The incident is the latest of several mishaps involving United planes coming to or going from Houston, including an injured disabled woman and a violinist who scuffled with United staff.