Just seen guys racing in on camels into Tahrir square to join the protests. Amazing sight.

But the situation is getting very tense. Aggressive pro-Mubarak supporters, some seemingly organized by the government, are driving into the square and coming face-to-face with angry anti-regime protesters.

The pro-government groups are much smaller than those calling for change, who gather in large clusters of 500 or more and then stream endlessly into the square.

It appears the numbers will easily beat those we saw yesterday.

But that makes the potential for violence even great as we reach a collateral mass of highly emotionally-charged people.