A high school student opened fire at a campus northwest of Bangkok on Friday, killing six people—three teachers and three students—and wounding fifteen others, police said.

The shooting occurred at Debsirin Nonthaburi School in Nonthaburi province. Royal Thai Police spokesperson Trairong Piwpan reported that fifteen people were injured in the attack, with two in critical condition. Authorities said the gunman was hospitalized in serious condition following the shooting.

Investigators believe the weapon used in the attack was taken from a member of the student’s family. Police stated that the official motive for the shooting remains under investigation.

Witnesses described students hiding inside classrooms while gunfire echoed through an adjacent building before police officers arrived to clear an evacuation path. Images from the scene showed first responders maneuvering through the campus while students and family members gathered outside.

Prime Minister Anutin Charnvirakul expressed his condolences to the families affected and directed state agencies to ensure support and medical care for the victims.