Technology: Introducing Anti-kidnap bracelets that tweet

Kidnapped aid workers could be saved by a new hi-tech bracelet which uses Facebook and Twitter to alert millions of people to a hostage crisis.

The device has been fitted with satellite navigation technology and is linked to social media so it can inform on an attack within seconds.The first Natalia Project bracelets are to be handed out this week in a bid to save lives in war zones where the risk of kidnap is high.

The Civil Rights Defenders campaign group, which has produced the bracelets, said the chunky gadgets can be triggered manually when an aid worker or civil rights activist comes under threat, or automatically if the bracelet is forcefully removed.

Each device is fitted with mobile phone technology which enables it to immediately send out a message to any near-by contacts and to the Civil Rights Defenders headquarters where the attack can be verified before a message is transmitted on social networking sites.At the same time, the bracelets issue the wearer's real-time GPS location so rescue teams can locate where the attack took place and its timing.