Massacre of the Ikhwan

Egypt's military has killed 51 Muslim Brothers at a sit-in to protest the coup which deposed Muhammad Morsi last week:

The mass shooting of Islamist protesters by security forces at a sit-in for ousted President Mohamed Morsi on Monday injected new outrage into the standoff over his removal by Egypt’s top generals, darkening hopes that they might reconcile the polarizing forces that have torn at the fabric of the country.

It was by far the deadliest day of violence since the revolt that overthrew former President Hosni Mubarak in January 2011. Within a few hours around dawn, advancing soldiers and police officers killed at least 51 people and wounded more than 400, almost all hit by gunfire, health officials said. 

Army and police spokesmen said that one soldier and two policemen also had been killed. But witnesses and video footage said one of the policemen appeared to have been shot by soldiers, and the military provided little evidence to back its claim that the fighting had been instigated by the Islamists. 

This is the same military that in October 2011 killed Copts at a peaceful protest, and there is at present to reason to believe that the Islamists were the instigators.  The Muslim Brotherhood is a highly disciplined protest force, and I just can't picture aggressive freelancing at one of their demonstrations.  What this will do is drive a wedge between the Islamists and Egypt's political process, pushing some in that political camp to violence, as we've already seen in the formation of this Ansar al-Sharia group.  It is a replay of Nasser's crackdown on the group, which led to the reactivation of militant special branches in the 1960's.

UPDATE: Juan Cole notes that there is some evidence the military may have been provoked.