The clashes erupted after supporters of Morsi tore down a stage belonging to leftist politician and ex-presidential candidate Hamdeen Sabbahi's Popular Current. The supporters of Sabbahi were chanting anti-Morsi slogans.
Tensions are also high after the country's Supreme Judiciary Council criticised the president's attempt to sack the country's top prosecutor.
Omar Rashid, the ambulance field supervisor in Tahrir Square, told Ahram Online that around a hundred had been hospitalised by late afternoon, mostly with head injuries.
"Hundreds more suffered different injuries," he said.
A number of people were shot with pellets by unknown assailants on Talaat Harb Street, while Molotov cocktails and rocks were being thrown in both Mohamed Mahmoud Street and Talaat Harb Street near Tahrir Square.
"Those who destroyed the stage are chanting for Morsi and beating up whoever chants against him," Mohamed Waked, a leading member of the National Front for Justice and Democracy, said via Twitter.
