UK Telegraph with every other major media outlet is reporting that Mubarak has called in the military, including tanks, and other sources report shoot-to-kill orders are issued. From the Telegraph:
Protesters cheering the police who joined them and hoisted them on their shoulders in one of the many dramatic and chaotic scenes across Egypt on Friday.
After chasing the police, thousands of protesters were able to flood into the huge Tahrir Square downtown after being kept out most of the day by a very heavy police presence. Few police could be seen around the square after the confrontation.