Hundreds of students were reportedly gathered at The Party Venue in Greenville, near Dallas, to celebrate the start of a new term at Texas A&M Commerce College, Independent reported.
It is unclear how many were in the building when someone with a rifle opened fire.
Fears that 20 or more people were shot appeared to be confirmed by officials in Hunt County, who told local media three air ambulances took some victims to a trauma hospital.
Others were taken to hospitals in Greenville, and neighboring Quinlan and Commerce, the officials told reporters at CBS' Dallas branch.
The shooter is reportedly still at large.