1.33pm:
Another update from Cairo from Jack Shenker:
Reports spreading of protesters attacking the council of ministers building downtown, while several thousands are marching towards Mubarak's presidential palace in Heliopolis. In Dar El Salaam, a densely-populated neighbourhood in southern Cairo, demonstrators claim they have taken over the police station.
There's a feeling of intense excitement on the streets here in Shubra, northern Cairo, as the police continue to stand back and allow protesters to pass - but some of the security forces are wearing bullet proof vests, and some fear this is the calm before the storm.
One former television news presenter told me she hadn't seen anything like this since 1977, when an uprising over bread prices almost brought down the government of President Sadat. But demonstrations remain cut off from each other and it's still too early to say how this will play out