A shooting at a high school in Nonthaburi province, just north of Bangkok, left seven people dead and at least 15 others injured on Friday morning, in one of the deadliest school shootings Thailand has recorded in recent years.

The gunfire broke out around 10 a.m. at Debsirin Nonthaburi School, a secondary school of roughly 3,000 students located along a busy highway in the Bang Kruai district. Volunteers from the Poh Teck Tung Foundation, a rescue organization that responds to emergencies across Bangkok and its suburbs, were among the first to reach the scene after reports of shots fired inside the building.

Officials said the dead include three teachers, three students and the suspected shooter, described by authorities as a student at the school. At least 15 people were wounded, two of them in critical condition, according to hospital officials treating the injured.

Accounts of exactly how the shooting ended have shifted through the day. Early reports from police said the suspect had been shot and killed, while later statements described him as being in critical condition and receiving emergency treatment, with some accounts suggesting he may have turned the gun on himself. Separately, police said a man and a woman were found dead at the suspected shooter's home, though officials have not yet said how those deaths relate to the school shooting. Investigators believe the weapon used was taken from a member of the suspect's family, though the exact circumstances and motive remain under investigation.

The attack is the second major school shooting to strike Thailand this year, after an earlier incident in Hat Yai, and comes as the country continues to grapple with gun violence despite some of the strictest firearms laws in Southeast Asia. Classes at Debsirin Nonthaburi School have been suspended as police continue processing the scene and interviewing witnesses.