The fourteen-year-old first shot and killed a man and a woman - his grandparents - in his home and then went to school.
There he killed five teachers and other school staff, Thai police say. At least 23 students were injured, ten of them seriously. The perpetrator was in grade nine, the equivalent of the same grade in Sweden, and is reported to have taken his own life in connection with the attack.
Comforted each other
Police and emergency workers gathered outside the school on Friday, while parents waited to pick up their children and crying students and staff comforted each other outside the school, according to AFP journalists at the scene.
Purin Khumchoo, 17, tells AFP that he nearly died during the shooting.
"I had a feeling he was a guy with problems. My friends who knew him said he was interested in the FBI and guns, and that he was bullied by a lot of other students," Purin Khumchoo told AFP outside the school.
When I saw him point the gun at me, he looked very professional, as if he had been practicing for a long time.
Prestigious school
The Debsirin Nonthaburi school where the incident occurred accepts students aged 12 to 18, and belongs to one of Thailand's oldest and most prestigious networks of public schools, with high-ranking politicians among its former students.
The suspected gunman used a handgun that was in the home and belonged to his grandfather, according to media reports. Thailand has one of the highest levels of gun ownership in the region, with about 10 million firearms in circulation. The country has been rocked by several high-profile mass shootings in recent years.
