London's first electric-powered black cabs hit the streets today, the British capital's iconic taxis getting a facelift for the modern age that should help cut pollution in the city.

The new-look cabs will meet the strict new emissions regulations required for all new London taxis from 2018.

They are replacing the old diesel cabs, with more than 9,000 electric taxis -- around half the current fleet size -- expected to be plying for trade by 2021.