What happens when pro-government protesters meet anti-government protesters in the streets of Cairo? Predictably, both sides get violent. CNN reports that for the moment the violence consists mostly of throwing shoes and rocks, but with no security to be seen at Tahrir Square, the violence is starting to spread:

This appears to be Hosni Mubarak’s answer to demands that he leave office immediately. Until yesterday, pro-government rallies had either not materialized or had been so low-key as to not attract much attention. Suddenly these rallies have begun appearing, and Tahrir Square is a high-profile location for them.

Why now? The army had already said that it would not intervene in the demonstrations as long as they remained peaceful and supported the “legitimate demands” of the people. If Mubarak wanted to get the army off the sidelines, the best way to do so would be to instigate violence and force the army’s hand.

However, that’s a dangerous game. Once violence starts, the leaders on the streets will be those most accustomed to it and most steeled against concerns over collateral damage. If the army doesn’t take the bait, what had been a pro-democracy push on the streets could easily turn into a radical Islamist putsch.

Update (AP): Your understatement of the day, courtesy of the Times: “President Obama’s calls for a rapid transition to a new order in Egypt seemed eclipsed on Wednesday as thousands of demonstrators for and against President Hosni Mubarak, some on horses and camels, fought running battles in and around Cairo’s Tahrir Square.” What’s the White House going to say about Mubarak rolling out his goon squad to clear the Square? Are we still in “orderly transition” mode, or is it now time for “Mubarak must go”?

Update (AP): Also, where’s the allegedly heroic Egyptian army while this is going on? Quote:

What about the Egyptian Army, which won accolades from the U.S. for not suppressing the anti-government demonstrations? It’s taking a hands-off approach, telling demonstrators that since everyone involved is a civilian, soldiers are not going to take sides. That’s according to anti-regime demonstrator Salma Eltarzi, who told Al Jazeera that she sees Mubarak’s game plan at work…

Al Jazeera reports that at least one building by the square has been set on fire. Coverage of the Army is now extremely critical: while soldiers have apparently set up some personnel carriers as barriers between the two sides, they haven’t stopped what the network described as a pro-government mob from pulling someone into its crowd and evidently beating him. Sultan al-Qassemi of The National tweets, referring to the defense minister and Army chief of staff, “Shame on the Egyptian Army. This is as low as they can get. What are Tantawi & Anan waiting for, a massacre or a stampede? Disgusting.”

Update (AP): Did the army know this was coming? A military spokesman went on TV this morning to tell protesters that their voices have been heard and that it’s now time to go home and restore “stability.” Maybe that was their way of trying to clear the Square peacefully before the goons rolled in and tried to do it by force.

Update (Ed): Reuters reports that shots have been fired in Tahrir Square, although no one knows by whom; the army denies firing any shots.