Watching the live video on Al Jazeera English live streaming link, and just now some of the pro-government counter-protestors (which witnesses say are actually government police) on the edges were trying to attack the mass of peaceful protestors. It appeared as though they were basically trying to de-stabilize the situation, and escalate things to violence.
More below the jump.
Some protestors on the edges began throwing rocks back at the attackers, and Egypt army tanks pulled in to calm things down. They fired some shots into the air, but are standing by their pledge to not fire on the protestors themselves.
The attackers from outside seem to have backed off for the moment, and the rock-throwing has stopped, and with the army tanks inserting themselves as a buffer, things seem to be calming down a bit.
More army vehicles and tanks are arriving, ostensibly as reinforcements to maintain some kind of order.
The protestors have been getting louder and louder, ever since President Mubarak gave a speech just about 90 minutes ago stating that while he wouldn't seek reelection, he also made clear he wasn't stepping down.
A pro-Mubarak group seems to be entering the square, chanting "We want Mubarak".
The video on-screen right now where all of this has been taking place seems to be happening in Alexandria, not in Cairo.
According to someone in Alexandria calling in on the phone, the entire thing may have been a misunderstanding between some of the neighborhood watch groups and gotten over-excited, causing the minor conflict for a few minutes. FYI, since the police had all kind of disappeared, many citizens had been forming neighborhood watch groups to help protect their property and that of their neighbors in case of looters, etc.
Not so sure about the veracity of that, as some rock-throwing has begun again, and army tanks are again firing over the heads of protestors, trying to calm things down again.
An Al Jazeera reporter is indicating that things are getting out of hand, as he is watching security getting geared up, putting on flack jackets, etc. He's now outside of Tahrir square, and was being passed by a pro-Mubarak crowd of some 300 people that is chanting things about defending Mubarak.
UPDATE: Now watching President Obama saying that transition of Egypt's regime "must begin now".
Watching this on Al Jazeera is downright refreshing, since I can only imagine the political head explosions that are probably happening on Fox Noise right now.