Multiple fatalities have been reported and a suspect is in custody after a shooting at a Texas high school.

Santa Fe High School was placed on lockdown following an "incident involving an active shooter" on Friday morning, according to the school district. A suspect was in custody, and a second one was detained, according to Harris County Sheriff Ed Gonzalez.

Follow latest updates after shooting attack at Santa Fe high school

Law enforcement sources told local news outlets that at least eight people had been killed. The school district confirmed that there were multiple people injured at the school, located about 40 miles south of Houston, but did not confirm any fatalities.Representatives from the University of Texas Medical Branch at Galveston said they had received three patients – two adults and one minor. The minor was admitted to the hospital while the adults were being treated in the emergency room.

A police officer was among those injured, according to Mr Gonzalez.