Yemen’s powerful Republican Guard forces opened fire with guns, tear gas and water cannons today at a march by more than 100,000 protesters demanding that the outgoing president be put on trial.

Heavy fighting has broken out in the Yemeni capital Sanaa between security forces and an army unit that joined the popular uprising against autocratic President Ali Abdullah Saleh.

The revolution against Mubarak did not have a figurehead; that was said to be key to its success. However, this strength has become a weakness in Egypt’s transition to democracy, writes Omar Ashour