With every step, she risks harassment or even arrest by Iran's morality police whose job is to enforce the strict dress code imposed after the 1979 Islamic Revolution.

"I have to confess it is really, really scary," the 30-year-old fire-safety consultant said in a WhatsApp audio message, speaking on condition of anonymity for fear of repercussions.

But she is also hopeful, saying she believes the authorities find it increasingly difficult to suppress protests as more women join in. "They are running after us, but cannot catch us," she said. "This is why we believe change is going to be made."