Scuffles between protesters and security forces erupt on Qasr El-Aini Street near Tahrir Square a few hours before thousands are scheduled to gather on the square to mark the revolution's 2nd anniversary Al Ahramonline reported.
Ahram Online reporter Zeinab El-Gundy on the scene says police forces are firing tear gas.
The clashes reportedly took place after a number of protesters attempted to bring down the wall built by security forces on the street adjacent to key government buildings.
Earlier on Thursday, two protesters were arrested by the police for trying to remove the wall which was built in November 2012 during Cairo's downtown street Mohamed Mahmoud's commemoration where clashes took place between Egypt's Central Security Forces (CSF) and protesters.