CAIRO, November 19 (Aswat Masriya) - Egyptian security forces have arrested four people who possessed weapons and hand-made grenades in Cairo's downtown near Tahrir Square, security sources told the state-owned news agency on Tuesday.

The security sources added that the detained people had three bags containing rubberbullets, one modified firearm, 12 handmade grenades and nine Molotov cocktail bottles.

Confrontations were renewed in downtown, where hundreds gathered to commemorate the two year anniversary of clashes between protesters and the security forces in Mohamed Mahmoud that left around 40 people dead.

At least 12 people were injured in clashes across Egypt, three of which in Tahrir Square, according to a health official.

On Monday night, dozens gathered around a foundation stone built to be memorial for martyrs, inaugurated earlier by army-backed interim Prime Minister Hazem el-Beblawi, and destroyed parts of it.

The protesters demanded retribution for the "martyrs before initiating the construction of any icons to of any icon to honour them.