"They joined the crowd, smiling, and chanted slogans calling for the fall of the regime," student Omar Gamal told AFP from Cairo's Tahrir Square, the focal point of the protests.

An AFP reporter saw one of the soldiers addressing the crowd to loud cheers. Protesters had spent the morning chanting for the army to join them in opposing the regime.

Nationwide anti-regime demonstrations erupted on January 25, leaving 300 people dead and many more injured or detained.