India, March 8 -- Revving round a dusty oval in the heart of Pakistan's largest city, women on motorbikes practise looping a row of safety cones, their helmets securing colourful headscarves in place.

It is a rare sight in the culturally conservative country, where women are typically relegated to the back seats of cars or to riding side-saddle on motorbikes, ferried by a male relative.

"Change is under way," says Zainab Safdar, demonstrating how to mount a two-wheeler while cloaked in a pink body-covering abaya.

The 40-year-old is an instructor for the "Rowdy Riders", a women-only group teaching novices in Karachi everything from the basics of balancing on a bicycle to high-octane gear changing and negotiating traffic.

Since being fo...