Clashes between protesters around Egypt's Ministry of Defence left twenty dead till now, according to protesters and the make shift hospital in the Abbassiyah square.
The health ministry insists there were only six dead. Soldiers and police have now stopped the clashes, but the intervention came nearly six hours after they began.
The health ministry said more than 150 people were injured today and that many were receiving treatment at a nearby field clinic. Some had gunshot wounds and others had been attacked with knives, according to medical sources.
Some reports also said the unidentified attackers were local people, angry at the disruption caused by the sit-in, which began on Saturday, the BBC reported.
Many of the protesters who were attacked this morning were supporters of a Salafist preacher, Hazem Abu Ismail, barred from standing in the election. They also demanded disbanding of the presidential election commission.
The protesters claim the thugs were backed by the army as they have been photographed in a number of protests before and some of them were arrested by protesters and confessed to have been paid by the army to attack the protests.
The army on the other hand insist they are neutral, have protected the revolution and want to turn the authority over to civilians as soon as possible with the presidential elections slated for May 23 and 24.
As a result of the clashes seven main parties including the Muslim Brotherhood, Justice party and Salafi Nur party decided to boycott the meeting with the Supreme Council of the Armed Forces (SCAF) today to decide on the principles governing the formation of the constituent assembly to draft the constitution.