Authorities say a mother and her two sons have died in a house fire in South Texas.

Guadalupe County Fire Marshal Kelly Kistner said the fire started Tuesday morning in the home located in a small neighborhood in an unincorporated area outside Seguin.

Kistner said one of the sons was 15 and the other was 5. He said he had yet to learn the age of the mother.

Kistner says the woman's 13-year-old daughter was also in the house, and is in stable condition at a Seguin hospital.

The names of the victims were not immediately released.

Firefighters from Sequin and nearby McQueeney fought the blaze.

Kistner said the cause of the fire is under investigation.

Seguin is about 40 miles east of San Antonio.