Santa Fe. Texas on Saturday (19/05) will likely release the names of nine students and a teacher killed by a gunman, identified by authorities as a 17-year-old student armed with a shotgun and pistol, who opened fire in a morning art class in his Houston-area high school.

Santa Fe High School, southeast of Houston, joined on Friday a long list of US campuses where students and faculty have been killed in mass shootings.

Shortly before 8 a.m., students said the gunman, identified by law enforcement as Dimitrios Pagourtzis, opened fire in an art class, sending students and staff fleeing.

Ten people were wounded, with several in critical condition.

It was fourth-deadliest mass shooting at a US public school in modern history, and again stoked the nation's long-running debate over gun ownership three months after 17 teens and educators were fatally shot in Parkland, Florida.

A vigil was held Friday night for the victims, who have not been officially identified. Local reports said those killed included a substitute art teacher and a Pakistani exchange student.

"This will bring us closer together - hopefully, a positive impact from something negative," said Clayton George, 16, who played football with the suspect.

Classmates described Pagourtzis as a quiet loner who played on the football team. On Friday, they said he wore a trench coat to school in Santa Fe, about 30 miles (50 km) southeast of Houston, on a day when temperatures topped 90 degrees Fahrenheit (32 degrees Celsius).

Texas Governor Greg Abbott said Pagourtzis obtained firearms from his father, who had likely acquired them legally, and also left behind explosive devices.

"Not only did he want to commit the shooting, but he wanted to commit suicide after the shooting," Abbott told reporters, citing a police review of the suspect's journals. "He didn't have the courage to commit suicide."

Pagourtzis was charged with capital murder and denied bail at a brief court hearing later on Friday, where he appeared in handcuffs and wearing a green prison jumpsuit. He spoke in a soft voice and said "Yes, sir" when asked if he wanted a court-appointed attorney, along with other questions.

Texas Attorney General Ken Paxton told CNN authorities were investigating whether anyone else helped in the attack.

Authorities have not disclosed how many explosive devices were found or if any of the deceased were killed or hurt by explosions. It is also unclear why the shooter targeted the art class.

"I wanted to take care of my friends, but I knew I had to get out of there," said Courtney Marshall, 15, who was in the class, adding that she saw at least one person hit. "I knew the guy behind me was dead."

Pagourtzis spared people he liked so he could have his story told, a charging document obtained by Reuters showed.

Abbott said investigators had seen a T-shirt on the suspect's Facebook page that read "Born to Kill," and authorities were examining his journal. But there were no outward signs he had been planning an attack, he said.

Some aspects of Friday's shooting had echoes of the massacre at Columbine High School in 1999. The two teenaged killers in that incident wore trench coats, used shotguns and planted improvised explosives, killing 10 before committing suicide themselves.

It was the second mass shooting in Texas in less than a year. A man armed with an assault rifle shot dead 26 people during Sunday prayers at a rural church last November.

Two school officers engaged the shooter, including school district police officer John Barnes, who was in critical condition after a gunshot wound to his elbow that almost caused him to bleed out, hospital officials said.

Authorities have not made public details of how they engaged the shooter.

Two others among the injured were also in critical condition.

Reuters