The government explains that the silent Cell Broadcast alerts sent to the public during the shooting at Thepsirin School in Nonthaburi were for safety reasons, to avoid increasing risk for people hiding in the area. It confirms that multiple alert formats exist.
On 8 August 2026, Ms. Lalida Pertwivatana, Deputy Spokesperson of the Prime Minister's Office, stated that following the shooting at Thepsirin School in Nonthaburi on 7 August 2026, the Department of Disaster Prevention and Mitigation (DDPM) used the Cell Broadcast system to alert residents in and around the area. The government clarifies this method after many inquiries about why these alerts had no sound unlike previous system tests, affirming the alert format was chosen based on safety principles to avoid increasing risk to those hiding in the incident area.
The Deputy Spokesperson explained that during the incident, the DDPM used Cell Broadcast to send alert messages to mobile phones within approximately a 5-kilometer radius around the school and nearby areas, requesting cooperation to avoid traveling to or entering the scene to reduce risks to the public and facilitate official operations.
This alert was a collaboration between the DDPM and mobile network providers. The Cell Broadcast system can simultaneously send messages directly to many mobile phones in the targeted area without needing to know recipients' phone numbers in advance. It also allows setting the area, alert format, and alert level according to the situation's nature.
The Deputy Spokesperson noted that a common public question was why these alerts lacked sound unlike previous system tests. The DDPM explained this was intentional; sending silent messages prevents phones of those hiding in the area from sounding alerts that might reveal their location and increase safety risks. This differs from natural disaster cases like earthquakes, tsunamis, or flash floods, where audible alerts are necessary to prompt immediate evacuation.
He added that the Cell Broadcast system is not one-size-fits-all. The choice of alert level, coverage area, and whether to use sound depends on the threat's characteristics. In armed attack situations, the priority is to warn outsiders to stay away without adding risk to those hiding inside the area.
The Cell Broadcast system is a rapid alert tool covering people in a target area without requiring registration or downloading additional apps. The government urges the public to carefully read alert messages, follow official instructions, avoid risky areas, and refrain from sharing images or live broadcasts of official operations, which could jeopardize the safety of personnel and residents.
In conclusion, the Deputy Spokesperson said this incident exemplifies adapting the Cell Broadcast system appropriately to different threat types. The government will continuously improve the system based on real-world experience to maximize alert effectiveness, ensure public safety, and suitably support all emergency situations.