MOSCOW, Oct 15 (Reuters) - Moscow"s sprawling metro network on Friday launched a fare payment system using facial recognition technology at its more than 240 stations, an initiative the authorities said was the first of its kind in the world. Moscow, a city of 12.7 million, has one of the world"s largest video-surveillance systems. It has used facial recognition technology to enforce COVID-19 quarantines, and protesters attending political rallies have also said police have used it to make preventive arrests and detentions. read more The authorities are now giving commuters the option to use facial recognition to pay their fare with a system called "Face Pay" at turnstiles equipped with cameras. "Moscow is the first city in the world where this system is operating on such a scale," Maxim Liksutov, head of the Russian capital"s transport department, said in a statement. Liksutov said the use of "Face Pay" was voluntary and that other payment methods remained in use. Prior to using the system, commuters must submit their picture and link it to their transport and bank cards via the Moscow Metro application. To use the metro, commuters registered with "Face Pay" simply need to look into a camera set up at a designated turnstile. The city"s transport department said commuters" data would be encrypted securely. Digital rights groups, however, say the system could undermine privacy and human rights. Roskomsvoboda, a group dedicated to protecting digital rights and freedom of information, has warned that Face Pay could be used for surveillance purposes. read more The Moscow mayor"s office announced it was rolling out a facial recognition system in the metro to spot wanted criminals in 2018, when Russia hosted the soccer World Cup.