UPDATE: 12:30 PM: CNN is reporting that at least 10 have been killed, most of them being students and at least have 12 have been hospitalized.

A 17-year-old male is in custody and another person of interest has been detained. Both are believed to be students.

Law enforcement are searching the premises for additional victims and explosives. The Santa Fe Independent School District urged those in the area via Twitter not to touch "any items out of place," as explosives have been found in areas off campus adjacent to the school.

The shooter used the fire alarm to lure staff and students out of classrooms. MaKenna Evans, a 16-year-old sophomore at Santa Fe High School, told CNN "she heard the fire alarm. When the students got outside, her principal told them all to run."

UPDATE 10:50 AM: Law enforcement officers are reporting that there are now between 8 -10 deaths. The student resource officer was shot and injured and another member of law enforcement officer was injured.

UPDATE:  As of 10 AM KHOU in Houston has reported that at least eight people are dead as a result of the shooting.

An active shooting today at a Texas High School. A spokesperson for the Sante Fe school district confirms an unspecified number of people have been wounded in a shooting at Sante Fe High School which is just outside of Galveston.

The Assistant Principal says the shooter "has been arrested and secured." The gunman apparently walked into an art class at Santa Fe High School and began firing what looked like a shotgun.

KHOU in Houston is reporting multiple fatalities.

One witness told KTRK she saw a girl shot in the leg.

Patients from the school are being taken to a hospital in the nearby city of Galveston, hospital spokesman Raul Reyes said. He did not say how many.

A suspect is in custody after a shooting at Texas' Santa Fe High School, according to Cris Richardson, the assistant principal. He told reporters assembled near the school that there was an active shooting, but "that person has been arrested and is secured."