with the soldiers' consent...,

NYTimes | Thousands of army troops stepped in late Friday to reinforce the police. By Saturday morning, a sense of celebration took over the central squares of the capital as at least some members of the military encouraged the protesters instead of cracking down on them.

It was unclear whether the soldiers in the streets were operating without orders or in defiance of them. But their displays of support for the protesters were conspicuous throughout the capital. In the most striking example, four armored military vehicles moved at the front of a crowd of thousands of protesters in a pitched battle against the Egyptian security police defending the Interior Ministry.

But the soldiers refused protesters’ pleas to open fire on the security police. And the police battered the protesters with tear gas, shotguns and rubber bullets. There were pools of blood in the streets, and protesters carried at least a dozen wounded from the front line of the clashes.

Everywhere in Cairo, soldiers and protesters hugged or snapped pictures together on top of military tanks. With the soldiers’ consent, protesters scrawled graffiti denouncing Mr. Mubarak on many of the tanks. “This is the revolution of all the people,” read a common slogan. “No, no, Mubarak” was another.

One camouflage-clad soldier shouted through a megaphone from the top of a tank: “I don’t care what happens, but you are the ones who are going to make the change!”

By Saturday night, informal brigades of mostly young men armed with bats, kitchen knives and other makeshift weapons had taken control, setting up checkpoints around the city.

Some speculated that the sudden withdrawal of the police from the cities — even some museums and embassies in Cairo were left unguarded — was intended to create chaos that could justify a crackdown. And reports of widespread looting and violence did return late Saturday night, dominating the state-controlled news media.

“How come there is no security at all?” asked Mohamed Salmawy, president of the Egyptian Writers Union. “It is very fishy that the police had decided to leave the country completely to the thugs and angry mobs.”

The Mubarak government may have considered its security police more reliable than the military, where service is compulsory for all Egyptian men. While soldiers occupied central squares, a heavy deployment of security police officers remained guarding several closed-off blocks around Mr. Mubarak’s presidential palace.