Protesters riot on Egypt's streets
Four people have died in the riots in Egypt. Protests are taking place because some people don't like the way the country is being run.
Lots of people in Egypt are very poor - many think that President Hosni Mubarak is treating them badly and not doing enough to make their lives better.
Police used water cannons to push protestors back.
On Wednesday the government there said it would punish anyone who takes part in public protests.
But some protesters tried to demonstrate anyway.
Armed police patrolling Cairo protests
The demonstrations were organised through social networking sites after people saw similar protests in Tunisia two weeks ago.
Those protests led to their president fleeing the country.
Demonstrations this size are very unusual for the country and everyone's watching to see what will happen next.