When a Nile of protesters flooded Cairo

More than a quarter-million people flooded Cairo's main square on Tuesday in a stunning and jubilant array of young and old, urban poor and middle class professionals, mounting by far the largest protest yet in a week of unrelenting demands for President Hosni Mubarak to leave after nearly 30 years in power.

The crowds - determined but peaceful - filled Tahrir, or Liberation, Square and spilled into nearby streets, among them people defying a government transportation shutdown to make their way from rural provinces.

Protesters jammed in shoulder-to-shoulder, with schoolteachers, farmers, unemployed university graduates, women in conservative headscarves and women in high heels, men in suits and working-class men in scuffed shoes.

They sang nationalist songs, danced, beat drums and chanted the anti-Mubarak slogan ''Leave! Leave! Leave!'' as military helicopters buzzed overhead.

Organisers said the aim was to intensify marches to get the president out of power by Friday, and similar demonstrations erupted in at least five other cities around Egypt.

Text: Agencies

Image: Young girls wave Egyptian flags atop an armoured vehicle just outside Tahrir or Liberation Square in Cairo, Egypt, on Tuesday, Feb 1, 2011. (Photographs copyright PTI)