What triggered the ‘Extremely Severe Alert’ on phones across India? All you need to know

Millions of mobile phone users across India received an emergency notification accompanied by a loud alarm or vibration on Saturday as part of a nationwide test of the Cell Broadcast Alert System conducted by the government.

The alert, titled “Extremely Severe Alerts”, was sent by the National Disaster Management Authority (NDMA) as part of efforts to strengthen emergency communication systems during disasters and other critical situations.

The message read:

“India, launches Cell Broadcast using indigenous technology, for instant disaster alerting service for its citizens. Alert citizens, safe nation.

No action is required by the public upon receipt of this message. This is a test message. – Government of India.”

The exercise was carried out by the Department of Telecommunications (DoT) under the Ministry of Communications in collaboration with the NDMA.

According to reports, the testing covered Delhi-NCR and the capital cities of states and Union Territories, excluding border areas and poll-bound states.

What is the Cell Broadcast Alert System?

The Cell Broadcast Alert System is designed to send emergency warnings directly to mobile phones located in a specific geographical area during disasters or other emergencies.

The system has been integrated with the alert platform ‘SACHET’, developed by the Centre for Development of Telematics (C-DOT).

Built using indigenous technology, the system can instantly send alerts to compatible mobile devices in affected areas. Unlike regular SMS messages, these alerts can override silent mode and do-not-disturb settings to ensure users notice them immediately.

The government said the technology is intended for time-sensitive emergencies including tsunamis, earthquakes, lightning strikes, cyclones, gas leaks and chemical hazards.

Why did phones make loud sounds?

Many users reported sudden loud alarms or strong vibrations when the alert arrived on their phones.

This happened because emergency broadcast alerts are designed to grab immediate attention during critical situations. The alerts can bypass certain phone settings so that emergency warnings are not missed.

Why some people received the alert multiple times

Authorities said users may receive multiple test alerts during the trial phase as mobile towers and networks across the country are being evaluated.

The Ministry of Communications said repeated alerts are expected during the testing process to ensure the system functions properly across the entire telecom infrastructure.

During the rollout phase, test messages may be sent in English, Hindi and regional languages.

Who received the alerts?

The test alerts were only sent to mobile phones where Cell Broadcast test alerts were enabled.

Users can manage these settings through their phone settings menu:

Settings → Safety and emergency → Wireless emergency alerts → Test alerts

How the system will work during real disasters

Once formally launched, the system is expected to automatically send emergency warnings to people located in affected areas within seconds of an incident.

The government said the aim is to improve disaster response communication and ensure that critical warnings reach citizens quickly during emergencies.

A wider disaster communication network

According to official information, disaster management authorities have already used alert systems to send more than 134 billion SMS alerts in over 19 Indian languages during natural disasters, cyclones and severe weather events.

The Cell Broadcast system is being introduced alongside the existing SMS-based warning network to improve the speed and reach of emergency communication.

The government said C-DOT has been entrusted with the indigenous development and implementation of the system as part of efforts to strengthen locally developed telecom technologies and infrastructure.

Authorities have repeatedly clarified that the messages received on Saturday were part of a planned nationwide testing exercise and required no action from the public.