A system that sends emergency alerts to mobile phones within areas affected by flooding, industrial accidents or other local risks is to be tested in the UK.
Government pilots in Easingwold, in North Yorkshire, Leiston, in Suffolk, and Glasgow city centre will evaluate how the public react to the alerts.
Up to 50,000 people will receive messages marked as a test this autumn.
The US, the Netherlands and Australia use a similar system, but one expert said it could be targeted by hackers.
The Cabinet Office, which announced the trials, said it was working with mobile phone operators O2, Vodafone and EE to conduct the experiment.
The tests will start later this month and continue into October and November.
Those sent the texts will be asked to provide feedback, and will also be encouraged to attend local focus groups. A report is expected in early 2014, after which ministers will decide whether to deploy the scheme.
Cabinet Office minister Chloe Smith told the BBC that the system, if put in place, would be used only in times of “genuine emergency”.
The trials come after the Strategic Defence and Security Review in 2010 set out the government’s commitment to “evaluate options for an improved public alert system”.
The trial will test two distinct methods of delivering emergency alerts to mobile phones.
The first uses traditional SMS, or text messaging, while the second uses cell broadcast (CB) technology, which operates on a dedicated network, not used for calls or texts.
While cell broadcast messages can only be sent by mobile operators and look slightly different to a conventional SMS, text messages can be sent by anyone – which means alerts could be impersonated.
“Spoofability will go through the roof if they use ‘plain Jane’ text messages,” said Chester Wisniewski, senior advisor at data security firm Sophos.
“Anything that carries the gravitas of a national alerts system will be a target for hackers.
“They are opening themselves up to vulnerabilities.”
Reacting to these claims, Ms Smith told the BBC that authorities “will be vigilant for any sign of abuse in the trial”.
She also assured that the mobile alerts would work alongside existing services, allowing members of the public to verify messages with other sources.
Mobile alert systems have already been used in several countries to alert people about disappearances, prison escapes, wanted vehicles.
Places which are prone to more serious natural disasters, such as Japan and Chile, are also implementing versions of the technology.
Californian Highway Patrol officials used the mobile alerts for the first time in the state one evening in August after two children went missing. Many people complained after they were woken by their phones buzzing and beeping.
However, there was more positive feedback a few weeks later when a 17-month-old missing toddler was reunited with her family in North Carolina after a message was sent to mobile phones in the area.
The Cabinet Office is proposing that the technology will only be used in the UK if there is a distinct threat to life or property.