BANG KRUAI, Thailand — A 14-year-old student killed five teachers and staff and wounded 23 people in a shooting at a school outside Bangkok on Friday, after fatally shooting his grandparents at their home, police said, in Thailand’s deadliest mass killing in nearly four years.
The teenager opened fire at Debsirin Nonthaburi School in Bang Kruai district, northwest of the capital, during classes, police said. The five people killed at the school were teachers and other staff members. Nine of those wounded were in critical condition, Prime Minister Anutin Charnvirakul said after consulting officials.
Police said the boy used a firearm belonging to his grandfather. Police Colonel Thadsakorn Konthong, superintendent of Bang Bua Thong Police Station, said the teenager had killed his grandparents at their home at about 5 a.m. before going to school.
“The firearm and the bullets belonged to the grandfather,” Thadsakorn told Reuters.
Police said the teenager fired at least 26 rounds at the school, with a further 34 rounds found afterward. He later shot himself and died in hospital, according to police.
Emergency workers treated wounded students and staff as police secured the school. Kiatikhun Verapongpradith, an emergency worker who responded to the scene, said his team treated students with injuries to their backs, chests and arms.
The shooting has prompted renewed scrutiny of gun access in Thailand, where civilian firearm ownership is high by regional standards. Anutin said the government would introduce a new firearms control law that would allow only government officials on duty to carry guns.
The prime minister said the teenager had been under stress related to his studies and described the attack as involving premeditation. Police are continuing to investigate the circumstances surrounding the shooting and the teenager’s access to his grandfather’s firearm.
The school had about 3,100 students and 147 teachers during the 2025 academic year, according to district authorities.
The attack was the second school shooting reported in Thailand this year. In February, a teacher was killed and a student wounded in a shooting at a school in Hat Yai in southern Thailand.
Thailand’s previous deadliest mass killing was in 2022, when a former police officer killed 36 people, including 22 children, in a gun-and-knife attack at a daycare centre and other locations in the northeastern province of Nong Bua Lamphu.
Authorities were continuing to investigate the Bangkok-area shooting on Saturday.
