The Alphabet Inc unit began offering fully automated rides, without attendants in the vehicle, to a few hundred early users of its robo-taxi service in Phoenix in October.

The company, which launched the first commercial automated ride-hailing service last December, now has over 1,500 monthly active riders - those who took at least one ride in the past 28 days.

(Reporting by Ayanti Bera in Bengaluru; Editing by Saumyadeb Chakrabarty)