US lawmakers in at least eight states are trying to mandate a "kill switch" for smartphones in an attempt to reduce thefts and robberies, local media reported on Monday.

Lawmakers in Connecticut, Illinois, Mississippi, Missouri, New Mexico, New York, Oregon and Virginia are working on bills to authorize software that can remotely disable stolen or lost devices, making them worthless to thieves.

California and Minnesota were the first two US states to adopt rules requiring smartphone manufacturers to make the "kill switch" function available in every device.

Those bills will be put into effect on July 1 this year.

Reports said last month that three cities - San Francisco, New York and London - had seen a dramatic decline in smartphone thefts and robberies since the wireless industry began to implement a "kill switch" on their devices, under Secure Our Smartphones, an international law-enforcing partnership aimed at deterring thefts.

Despite initial opposition from major US wireless carriers, who were particularly against state-level mandates for the technology, some of them are now willing to introduce similar solutions to curb phone thefts.

Lost and stolen mobile devices in 2013 were estimated to have been valued at more than $30 billion in the US.

(China Daily 04/01/2015 page12)