More than 250,000 protest in Cairo's main square

More than 250,000 people joined a mass protest in Cairo's main square today in the largest protest yet in a week of unrelenting demands for Egyptian President Hosni Mubarak to leave after nearly 30 years in power.

The crowds - a huge array of young and old, urban poor and middle class professionals - filled Tahrir, or Liberation, Square and spilled into nearby streets in a determined but peaceful protest.