Stones fly through the air as supporters of President Hosni Mubarak, foreground , fight with anti-Mubarak protesters, rear, standing on army tanks in Cairo, Egypt, Wednesday, Feb.2, 2011. Several thousand supporters of  Mr. Mubarak, including some riding horses and camels and wielding whips, clashed with anti-government protesters Wednesday as Egypt's upheaval took a dangerous new turn. (AP Photo/Ahmed Ali)

Photo by: Ahmed Ali

Stones fly through the air as supporters of President Hosni Mubarak, foreground , fight with anti-Mubarak protesters, rear, standing on army tanks in Cairo, Egypt, Wednesday, Feb.2, 2011. Several thousand supporters of Mr. Mubarak, including some riding horses and camels and wielding whips, clashed with anti-government protesters Wednesday as Egypt's upheaval took a dangerous new turn. (AP Photo/Ahmed Ali)