Last winter, an Egyptian woman was assaulted by a crowd of men in the city of Alexandria.

In video footage of the incident, posted on the internet, she is hauled over men's shoulders and dragged along the ground, her screams barely audible over the shouts of the mob.

It is hard to tell who is attacking her and who is trying to help.

The case was one of the most extreme - but surveys say many Egyptian women face some form of sexual harassment every day.

Marwa, not her real name, says she worries about being groped or verbally harassed whenever she goes downtown. She says it makes her afraid.

"This is something that scares me, as a girl. When I want to go out, walking the street and someone harasses or annoys me, it makes me afraid.

"This stops me from going out. I try to be excessively cautious in the way I dress so I avoid wearing things that attract people."

'Deeply rooted'

The day I met Marwa, she was wearing a long headscarf pinned like a wimple under her chin, and a loose flowing dress with long sleeves over baggy trousers.

But dressing conservatively is no longer a protection, according to Dina Farid of the campaign group Egypt's Girls are a Red Line.

She says even women who wear the full-face veil - the niqab - are being targeted.