Vulnerable children living in one of China's poorest areas are receiving wearable high-tech devices to help keep them safe.

About 100,000 primary school students in Bijie, Guizhou province, will receive new watch-phones fitted with satellite tracking that can provide real-time information on their whereabouts to parents, guardians, officials and teachers.

All of the children have been left behind in towns and villages by parents who have moved away for work, so the phones will also make it easier for these families to stay in contact, according to a statement from the city government.